function wpfme_has_sidebar($classes) {
    if (is_active_sidebar('sidebar')) {
        // add 'class-name' to the $classes array
        $classes[] = 'has_sidebar';
    }
    // return the $classes array
    return $classes;
}
add_filter('body_class','wpfme_has_sidebar');

Thanks to WP Function for the tip!

To enter, simply tweet anything including our partner url: http://www.wpthemegenerator.com. Then, leave a comment on this page so I'll have your email address. In one week (May 25), I'll pick 5 winners using Random.org and they'll receive their prizes directly from the WP Theme Generator staff.

Some more info about WP Theme Generator

WordPress Theme Generator is a master tool to create and design custom themes, for it comprises more than 1000 design elements at your disposal and supports your own uploaded designs if so you wish. Additionally you can download all your themes –with a full-of-features framework– or save them for later review or edition, both in WP or HTML, and while they are being kept within the tool’s interface, they are kept up-to-date with the latest framework releases. If time is of the essence and an even faster solution is required there's a public themes gallery which has hundreds of professionally pre-designed themes that include layered .psd files.

WordPress Theme Generator main features

• 1000+ Pre-designed elements
• New design elements added daily
• Change any design aspect with an easy to use interface
• 50+ preloaded fonts to to choose from
• Unlimited sidebars or widget areas
• Saving, editing and downloading of the themes
• Download in both WP & HTML/CSS
• Always updated with the latest WP version
• A powerful framework behind
• Check all features

Take a look to the WordPress Theme Generator.

function create_meta_desc() {
    global $post;
if (!is_single()) { return; }
    $meta = strip_tags($post->post_content);
    $meta = strip_shortcodes($post->post_content);
    $meta = str_replace(array("\n", "\r", "\t"), ' ', $meta);
    $meta = substr($meta, 0, 125);
    echo "<meta name='description' content='$meta' />";
}
add_action('wp_head', 'create_meta_desc');

Thanks to Paul for this handy snippet!

add_filter( 'post_thumbnail_html', 'remove_width_attribute', 10 );
add_filter( 'image_send_to_editor', 'remove_width_attribute', 10 );

function remove_width_attribute( $html ) {
   $html = preg_replace( '/(width|height)="\d*"\s/', "", $html );
   return $html;
}

Thanks to Damien for the cool hack!

<?php
   if (is_plugin_active('plugin-directory/plugin-file.php')) {
      // the plugin is active
   }
?>

Thanks to Cats Who Code for the cool tip!

// set arguments for get_posts()
$args = array(
    'numberposts' => 1,
    'orderby' => 'rand'
);

// get a random post from the database
$my_random_post = get_posts ( $args );

// process the database request through a foreach loop
foreach ( $my_random_post as $post ) {
  // redirect the user to the random post
  wp_redirect ( get_permalink ( $post->ID ) );
  exit;
}

Once done, upload the page-random.php file to your theme directory. Then, login to your WordPress dashboard and create a new page, called "random" (You have to call it random, otherwise, the standard page layout will apply, see WP Codex for more details about page hierarchy).

After you published the random page, any user who'll visit the http://www.yourwebsite.com/random page will be automatically redirected to a random post.

By the way, I just created a Facebook page for my websites (This include WPRecipes as well as CatsWhoCode) so don't hesitate to "like" it!

Thanks to Smashing Magazine for the cool tip!

remove_action( 'load-update-core.php', 'wp_update_plugins' );
add_filter( 'pre_site_transient_update_plugins', create_function( '$a', "return null;" ) );

Thanks to WP Snippets for the useful tip!

add_filter('gettext',  'change_post_to_article');
add_filter('ngettext',  'change_post_to_article');

function change_post_to_article($translated) {
     $translated = str_ireplace('Post',  'Article',  $translated);
     return $translated;
}

Thanks to Smashing Magazine for the cool tip!

global $wp_query;
$total = $wp_query->max_num_pages;
// only bother with the rest if we have more than 1 page!
if ( $total > 1 )  {
     // get the current page
     if ( !$current_page = get_query_var('paged') )
          $current_page = 1;
     // structure of "format" depends on whether we're using pretty permalinks
     $format = empty( get_option('permalink_structure') ) ? '&page=%#%' : 'page/%#%/';
     echo paginate_links(array(
          'base' => get_pagenum_link(1) . '%_%',
          'format' => $format,
          'current' => $current_page,
          'total' => $total,
          'mid_size' => 4,
          'type' => 'list'
     ));
}

Thanks to Smashing Magazine for the cool tip!

add_filter('jpeg_quality', function($arg){return 100;});

Save the file, and you're done. That's simple as that!

Thanks to WP Snippets for the tip!