Let's say that you want to change the default setting from 30 days to 7 days. Add the following to the wp-config.php file ...

define('EMPTY_TRASH_DAYS', 7 );

You can adjust the number to anything you want. If you want to disable Trash change the number to 0 as such ...

define('EMPTY_TRASH_DAYS', 0 );

To see a cool list of configuration settings that can be set/changed via wp-config check out the documentation at the Codex.

In a plain text editor such as Notepad, open your theme's functions.php and add the following ...

//delay feed publishing
function publish_later_on_feed($where) {
global $wpdb;

if ( is_feed() ) {
// timestamp in WP-format
$now = gmdate('Y-m-d H:i:s');

// value for wait; + device
$wait = 'x'; // integer

// http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_timestampdiff
$device = 'MINUTE'; //MINUTE, HOUR, DAY, WEEK, MONTH, YEAR

// add SQL-sytax to default $where
$where .= " AND TIMESTAMPDIFF($device, $wpdb->posts.post_date_gmt, '$now') > $wait ";
}
return $where;
}

add_filter('posts_where', 'publish_later_on_feed');

What we have done is add a filter to the publish_later_on_feed function so that your feed is not published at the same time your post is. You can adjust the time delay to anything you want. Look for the line,

$wait = 'x'; // integer and change x accordingly. For instance, if you wanted a 30 minute delay that line would look like,

$wait = '30'; // integer

All we need to do is add a bit of code to the active theme's functions.php file. Before we begin be sure to backup that file. If you make a mistake you may bork your entire site. Open the active theme's functions.php file in a plain text editor and add the following...

//disable feed
function fb_disable_feed() {
	wp_die( __('<strong>Error:</strong> No RSS feed available, please visit our <a href="'. get_bloginfo('url') .'">homepage</a> for the latest articles!') );
}

add_action('do_feed', 'fb_disable_feed', 1);
add_action('do_feed_rdf', 'fb_disable_feed', 1);
add_action('do_feed_rss', 'fb_disable_feed', 1);
add_action('do_feed_rss2', 'fb_disable_feed', 1);
add_action('do_feed_atom', 'fb_disable_feed', 1);

Now when you click one of your RSS links you will see the following message, (click image to enlarge)

If you want to reactivate the feed simply delete the code you added to the functions.php file. It goes without saying this is theme-specific. That is, if you change themes you'll have to add the code to that theme's functions.php file as well. Or, you could make a plugin out of this and drop it in your plugin folder. That way it will work regardless of the theme you are using. It's much easier to turn off as well.

Upon re-reading my post it occurred to me some of you may not know how to turn this in to a plugin. Fear not for I have done it for you. You can get Feed Killer from the Downloads page. [currently unavailable] Simply download the ZIP to your computer, extract the file feed_killer.php and upload it to your plugin folder. Activate as you would any other plugin. To turn your feed back on deactivate the plugin. I should have searched the WordPress plugin repo prior to doing this as such a plugin already exists. You can download it there.

Edit: New information has come to my attention as to the original author of the snippet above. Thanks to Alex at WP Engineer.com!

One option is to click the Screen Options button at the top of the page which reveals all available dashboard widgets, each with a nifty check box beside its name. Simply unchecking the appropriate box will hide the widget from your Dashboard. To re-enable it tick the box. See screen shot below. (click image to enlarge)

But what if, for some reason, you want to completely disable one or more widgets as opposed to hiding them? Sure you can do so by hacking core files but this is not recommended. A better option is to add a bit of code to your theme's functions.php file.

First, let's take a look at what the Codex has to say about Dashboard Widgets. Here are the names of the meta boxes on the dashboard:

Main column
$wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']
$wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments']
$wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']
$wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']

Side Column
$wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']
$wp_meta_boxes['dashboard']['side']['core']['dashboard_recent_drafts']
$wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']
$wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']

To remove select items we will manually unset() their items from the general $wp_meta_box array via the theme's functions.php file.

Using the example provided by the Codex, to remove the quickpress and incoming_links widgets, add the following to your theme's functions.php file,

// Create the function to use in the action hook

function example_remove_dashboard_widgets() {
	// Globalize the metaboxes array, this holds all the widgets for wp-admin

	global $wp_meta_boxes;

	// Remove the quickpress widget

	unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);

	// Remove the incomming links widget

	unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);
} 

// Hoook into the 'wp_dashboard_setup' action to register our function

add_action('wp_dashboard_setup', 'example_remove_dashboard_widgets' );

Look at the above carefully. Recall that the meta box for the quick_press widget is...

$wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']

See how we manually remove it via unset() as such...

unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);

You can follow this example to disable each of the widgets. In a local install I disabled all dashboard widgets. See the screen shot below. (click image to enlarge)

I accomplished this by making use of the info earlier in this post then by adding the following to my theme's functions.php file...

// Create the function to use in the action hook

function example_remove_dashboard_widgets() {
	// Globalize the metaboxes array, this holds all the widgets for wp-admin

	global $wp_meta_boxes;

	// Remove the quickpress widget

	unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);

	// Remove the recent drafts widget

	unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_recent_drafts']);

	// Remove the wordpress dev blog widget

	unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);

	// Remove the other wp news widget

	unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);

	// Remove the incomming links widget

	unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);

	// Remove the dashboard right now widget

	unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);

	// Remove the recent comments widget

	unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments']);

	// Remove the plugins widget

	unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);
} 

// Hoook into the 'wp_dashboard_setup' action to register our function

add_action('wp_dashboard_setup', 'example_remove_dashboard_widgets' );

To re-enable any of the widgets simply remove the appropriate code from the functions.php file. To re-enable all of them remove all of the code.

Further reading: http://codex.wordpress.org/Dashboard_Widgets_API

Although there are legitimate cases of wanting to change the Blog address (URL), such as when you are planning to give WordPress its own directory, for the vast majority of users however the values depicted in the image above should be left alone. It's when people start changing them that chaos ensues. Fortunately the fix is an easy one. In this post I'll give you three different methods for changing the values back to what they should be should you find yourself locked out of your blog.

Method #1: Edit wp-config.php
This is probably the easiest method of the three. Open the wp-config.php file in a plain text editor such as Notepad and add the following lines ...

define('WP_HOME','http://yoursite.com');
define('WP_SITEURL','http://yoursite.com');

... where yoursite.com is the correct URL. It goes without saying you will need to log in to your site via FTP.

Method #2: Edit the active theme's functions.php file
This method is a bit more involved than the previous one but is still fairly straightforward. We will need to edit the functions.php file of the currently active theme. If it doesn't exist then we'll need to create it. It's important to note it must belong to the currently active theme.

Okay, open functions.php in a plain text editor and immediately after the line containing the opening <?php tag add the following ...

update_option('siteurl','http://yoursite.com');
update_option('home','http://yoursite.com');

... where once again yoursite.com is the correct URL.

If the active theme doesn't have its own functions.php file don't worry it's easy to create. In a plain text editor create a file called functions.php and add the following to it ...

<?php
update_option('siteurl','http://yoursite.com');
update_option('home','http://yoursite.com');

Upload the file to the active theme directory.

Method #3: Edit the database
Although this method can seem very daunting, even downright terrifying to newbies, it's not that difficult. One thing to remember - you will be directly interacting with your database. There is no undo. If you make a mistake the consequences could be disastrous. Prior to manipulating your database, and I can't stress this enough, create a backup. You will find easy step by step instructions at the Codex. Scroll down to the section called Backup Documentation.

Now that I've scared the jeebus out of you let's proceed. For this example we will be using phpMyAdmin - a program for manipulating the MySQL database.

Log in to your host's phpMyAdmin and select the appropriate database. See screenshot below. (click to enlarge)

Obviously your environment will most likely look different. I have a bunch of local WordPress installs hence the reason for all of those databases.

Once you have selected your database you will come to a screen like the one below. (click to enlarge)

Keeping the image above in mind you need to click the Browse button of the wp_options table. Now, your table prefix may or may not be wp_ depending on if you manually changed them to something else. For the purposes of this article we'll assume not.

After clicking the browse button of the wp_options table you will see the screen below. (click to enlarge)

Upon clicking the pencil icon you will see the screen below. (click to enlarge)

Once you changed the siteurl value back to what it should be all you need to do is go back to the wp_options table, look for home and do the same thing.

Backup Your Database
This should be your first step. Whenever interacting directly with your database via a tool like phpMyAdmin always backup your database. It can save you much grief later.

Edit the wp-config file
Open the wp-config.php file in a plain text editor and at or about Line 57 you will see...

$table_prefix = 'wp_';

change that to something a bit more obscure like...

$table_prefix = '6EW6xEjuC_';

It's important to note you can only use letters, numbers and underscores. Once complete put the file away as we are finished with it.

Rename Your Tables
This is the fun part. Don't worry, it's an easy procedure. Fire up phpMyAdmin and select your database. Click on the SQL Query icon to launch a new window. See image below.

A default installation of WordPress will have 10 tables. Your install may have more depending on what plugins you use but any additional tables will also have to be renamed.

When you click the SQL Query icon a new window will open. In that window enter the command to rename your tables one at a time. This is the data you need to change...

Rename table wp_comments to 6EW6xEjuC_comments;
Rename table wp_links to 6EW6xEjuC_links;
Rename table wp_options to 6EW6xEjuC_options;
Rename table wp_postmeta to 6EW6xEjuC_postmeta;
Rename table wp_posts to 6EW6xEjuC_posts;
Rename table wp_terms to 6EW6xEjuC_terms;
Rename table wp_term_relationships to 6EW6xEjuC_term_relationships;
Rename table wp_term_taxonomy to 6EW6xEjuC_term_taxonomy;
Rename table wp_usermeta to 6EW6xEjuC_usermeta;
Rename table wp_users to 6EW6xEjuC_users;

For instance, click the SQL Query icon to launch a new window. In that window enter...

Rename table wp_comments to 6EW6xEjuC_comments;

then click Go. You will see the newly renamed table. See image below. (click to enlarge)

Do this one at a time until all tables have been renamed.

Edit wp_options
You now need to edit some data in the wp_options table which should actually now be called 6EW6xEjuC_options. Select the 6EW6xEjuC_options table and click the Browse icon. See image below. (click to enlarge)

After clicking the Browse icon you will see a new screen. Under the option_name heading at the top, search for wp_user_roles and change it to 6EW6xEjuC_user_roles. See image below. (click to enlarge)

Referencing the image above, click the Pencil icon in the wp_user_roles row. You will see a new screen. See image below. (click to enlarge)

Edit wp_usermeta
This is the final step. Change the data contained within the wp_usermeta table which should now be called 6ew6xejuc_usermeta. Click the Browse icon next to the 6ew6xejuc_usermeta table. See image below. (click to enlarge)

After clicking the Browse icon you will see a screen similar to the one below. (click to enlarge)

Referencing the above image, search under the meta_key heading and change all values starting with the old wp_ prefix. For instance, in the above image you want to change wp_capabilities to 6EW6xEjuC_capabilities and wp_user_level to 6EW6xEjuC_user_level. You do so by clicking the Pencil icon in the appropriate row. It's important to note your install may have more data than is shown above. If so, you need to change that as well. The example I'm using is a default, no-frills install.

Clicking the Pencil icon in the wp_capabilities row will bring up the screen below. (click to enlarge)

Do this for each applicable row until done. That's it.

<?php wp_list_pages('title_li='); ?>

The parameter title_li sets the text and style of the list's heading. The default reverts to 'Pages' but if left blank as above nothing is displayed. Thus using wp_list_pages with the parameter title_li= will render a list of pages with no heading.

What if we wanted to insert a special character such as ' | ' or ' // ' between the individual menu items? Do we then have to manually code our navigation menu? Not at all. All we need to do is make a slight modification. Take a look at the code below...

<?php
$char = ' // ';
wp_list_pages('link_before=<li>&link_after='.$char.'</li>');
?>

What this will do is generate a list of pages with // between each menu item. Cool, yes? How do we use this with the title_li parameter? Let's throw a couple of things into the mix so you better understand the string. Let's use the parameters title_li and exclude with the above code. It would now look like...

<?php
$char = ' // ';
wp_list_pages('title_li=&exclude=1050,1255&link_before=<li>&link_after='.$char.'</li>');
?>

What this will do is generate a list of pages, with no heading and omitting the pages with the numerical ID of 1050 and 1255 while inserting // between each menu item. You can use as many parameters as you want - just be sure to preface each one with &. Let's see a screen shot of what it looks like. (click image to enlarge)

How did I do this? WordPress already comes bundled with Thickbox. It is how theme previews etc are displayed. All we need to do is call Thickbox then add the class "thickbox" to the href tag linking the larger image.

First, add the following to your theme's functions.php file,

function theme_queue_js(){
  if (!is_admin()){
    wp_enqueue_script('jquery');
    add_thickbox();
    wp_enqueue_style('thickbox');
}
}

add_action( 'get_header', 'theme_queue_js' );

Now all you need to do is add class="thickbox" to the href tag linking your larger image. For example, the code for displaying the above image is...

<a href="http://wpcanada.ca/wp-content/uploads/2009/11/glasses.jpg"><img src="http://wpcanada.ca/wp-content/uploads/2009/11/glasses-300x200.jpg" alt="glasses" title="glasses" width="300" height="200" class="aligncenter size-medium wp-image-1899" /></a>

The image displayed is a medium sized image (300x200 px) and is called by the img tag. It is linked to the full sized image as stipulated in the href tag. We add class="thickbox" to the href tag as such...

<a class="thickbox" href="http://wpcanada.ca/wp-content/uploads/2009/11/glasses.jpg"><img src="http://wpcanada.ca/wp-content/uploads/2009/11/glasses-300x200.jpg" alt="glasses" title="glasses" width="300" height="200" class="aligncenter size-medium wp-image-1899" /></a>

If you're looking for something a little fancier you might want to use a plugin but for basic functionality this works fine.

This post is password protected. To view it please enter your password below:

This is determined by Line 1146 at wp-includes/post-template.php. What if you wanted to change that output to something else? One solution would be to simply edit Line 1146 at wp-includes/post-template.php. Of course editing core files is never a good idea unless you know what you are doing. A much better solution is to create a new function and add a filter.

Add the following to your theme's functions.php file,

add_filter( 'the_password_form', 'custom_password_form' );
function custom_password_form() {
	global $post;
	$label = 'pwbox-'.( empty( $post->ID ) ? rand() : $post->ID );
	$o = '<form class="protected-post-form" action="' . get_option('siteurl') . '/wp-pass.php" method="post">
	' . __( "This post is password protected. To view it please enter your password below:" ) . '
	<label for="' . $label . '">' . __( "Password:" ) . ' </label><input name="post_password" id="' . $label . '" type="password" size="20" /><input type="submit" name="Submit" value="' . esc_attr__( "Submit" ) . '" />
	</form>
	';
	return $o;
}

Edit the appropriate text above.

Note that the new function has been assigned a class > protected-post-form. To make use of this simply add .protected-post-form to your theme's style sheet along with whatever styling rules you want. For instance, using the default Kubrick theme I added the following to the style sheet,

.protected-post-form {
      background:#FF0000;
      color:#fff;
      border:1px solid #000;
}

This is the result, (click image to enlarge)

via the WordPress Support Forum.

Why do this? If you have a regular following it's a way to create a little suspense for your readers. Add the following to sidebar.php ...

<?php
$my_query = new WP_Query('post_status=future&order=DESC&showposts=5');
if ($my_query->have_posts()) {
while ($my_query->have_posts()) : $my_query->the_post(); ?>
   <?php the_title(); ?>
<?php endwhile;
}
?>

This will pull the latest 5 scheduled posts from the database and display their titles. You could use a heading like "Coming Soon.."