WordPress/wp-content/themes/twentyten/functions.php

<?php

// Set the content width based on the Theme CSS
$content_width = apply_filters('twentyten_content_width', 640 );

// Your Changeable header business starts here
// No CSS, just IMG call
define( 'HEADER_TEXTCOLOR', '');
define( 'HEADER_IMAGE', '%s/images/header-1.jpg'); // %s is theme dir uri
define( 'HEADER_IMAGE_WIDTH', apply_filters( 'twentyten_header_image_width',  940 ) );
define( 'HEADER_IMAGE_HEIGHT', apply_filters( 'twentyten_header_image_height',  198 ) );
define( 'NO_HEADER_TEXT', true );

function twentyten_admin_header_style() {
?>
<style type="text/css">
#headimg {
	height: <?php echo HEADER_IMAGE_HEIGHT; ?>px;
	width: <?php echo HEADER_IMAGE_WIDTH; ?>px;
}
#headimg h1, #headimg #desc {
	display: none;
}
</style>
<?php
}

add_custom_image_header('', 'twentyten_admin_header_style');
// and thus ends the changeable header business

add_custom_background();

// This theme needs post thumbnails
add_theme_support( 'post-thumbnails' );

// We'll be using them for custom header images on posts and pages
// so we want them to be 940 pixels wide by 198 pixels tall (larger images will be auto-cropped to fit)
set_post_thumbnail_size( HEADER_IMAGE_WIDTH, HEADER_IMAGE_HEIGHT, true );

// Make theme available for translation
// Translations can be filed in the /languages/ directory
load_theme_textdomain( 'twentyten', TEMPLATEPATH . '/languages' );

$locale = get_locale();
$locale_file = TEMPLATEPATH . "/languages/$locale.php";
if ( is_readable($locale_file) )
	require_once($locale_file);



// Get the page number
function get_page_number() {
	if ( get_query_var('paged') )
		print ' | ' . __( 'Page ' , 'twentyten') . get_query_var('paged');
} // end get_page_number



// Control excerpt length
function new_excerpt_length($length) {
	return 40;
}
add_filter('excerpt_length', 'new_excerpt_length');



// Make a nice read more link on excerpts
function new_excerpt_more($more) {
	return '&nbsp;&hellip; <a href="'. get_permalink() . '">' . 'Continue&nbsp;reading&nbsp;<span class="meta-nav">&rarr;</span>' . '</a>';
}
add_filter('excerpt_more', 'new_excerpt_more');



// Template for comments and pingbacks
function twentyten_comment($comment, $args, $depth) {
	$GLOBALS ['comment'] = $comment; ?>
	<?php if ('' == $comment->comment_type) { ?>
	<li <?php comment_class(); ?> id="li-comment-<?php comment_ID() ?>">
		<div id="comment-<?php comment_ID(); ?>">
		<div class="comment-author vcard">
			<?php echo get_avatar($comment,$size='40'); ?>

			<?php printf(__('<cite class="fn">%s</cite> <span class="says">says:</span>'), get_comment_author_link()) ?>
		</div>
		<?php if ($comment->comment_approved == '0') : ?>
			<em><?php _e('Your comment is awaiting moderation.') ?></em>
			<br />
		<?php endif; ?>

		<div class="comment-meta commentmetadata"><a href="<?php echo htmlspecialchars( get_comment_link( $comment->comment_ID ) ) ?>"><?php printf(__('%1$s at %2$s'), get_comment_date(),  get_comment_time()) ?></a><?php edit_comment_link(__('(Edit)'),'  ','') ?></div>

		<div class="comment-body"><?php comment_text() ?></div>

		<div class="reply">
			<?php comment_reply_link(array_merge( $args, array('depth' => $depth, 'max_depth' => $args['max_depth']))) ?>
		</div>
	</div>

	<?php } else { ?>
	<li class="post pingback">
		<p><?php _e('Pingback:') ?> <?php comment_author_link ()?><?php edit_comment_link ( 'edit', '&nbsp;&nbsp;', '' ); ?></p>
	<?php }
}



// Make the Visual Editor styles match the theme's styles
	add_filter('mce_css', 'my_editor_style');
	function my_editor_style($url) {

		if ( !empty($url) )
			$url .= ',';

	// Change the path here if using sub-directory
	$url .= trailingslashit( get_stylesheet_directory_uri() ) . 'editor-style.css';

	return $url;
}



// Remove inline styles on gallery shortcode

function remove_gallery_css() {
	return "<div class='gallery'>";
}
add_filter('gallery_style', 'remove_gallery_css');



// For category lists on category archives: Returns other categories except the current one (redundant)
function cats_meow($glue) {
	$current_cat = single_cat_title( '', false );
	$separator = "\n";
	$cats = explode( $separator, get_the_category_list($separator) );
	foreach ( $cats as $i => $str ) {
		if ( strstr( $str, ">$current_cat<" ) ) {
			unset($cats[$i]);
			break;
		}
	}
	if ( empty($cats) )
		return false;

	return trim(join( $glue, $cats ));
} // end cats_meow



// For tag lists on tag archives: Returns other tags except the current one (redundant)
function tag_ur_it($glue) {
	$current_tag = single_tag_title( '', '',  false );
	$separator = "\n";
	$tags = explode( $separator, get_the_tag_list( "", "$separator", "" ) );
	foreach ( $tags as $i => $str ) {
		if ( strstr( $str, ">$current_tag<" ) ) {
			unset($tags[$i]);
			break;
		}
	}
	if ( empty($tags) )
		return false;

	return trim(join( $glue, $tags ));
} // end tag_ur_it


// Register widgetized areas
function theme_widgets_init() {
	// Area 1
	register_sidebar( array (
		'name' => 'Primary Widget Area',
		'id' => 'primary-widget-area',
		'description' => __('The primary widget area' , 'twentyten'),
		'before_widget' => '<li id="%1$s" class="widget-container %2$s">',
		'after_widget' => "</li>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

	// Area 2
	register_sidebar( array (
		'name' => 'Secondary Widget Area',
		'id' => 'secondary-widget-area',
		'description' => __('The secondary widget area' , 'twentyten'),
		'before_widget' => '<li id="%1$s" class="widget-container %2$s">',
		'after_widget' => "</li>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

	// Area 3
	register_sidebar( array (
		'name' => 'First Footer Widget Area',
		'id' => 'first-footer-widget-area',
		'description' => __('The first footer widget area' , 'twentyten'),
		'before_widget' => '<li id="%1$s" class="widget-container %2$s">',
		'after_widget' => "</li>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

	// Area 4
	register_sidebar( array (
		'name' => 'Second Footer Widget Area',
		'id' => 'second-footer-widget-area',
		'description' => __('The second footer widget area' , 'twentyten'),
		'before_widget' => '<li id="%1$s" class="widget-container %2$s">',
		'after_widget' => "</li>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

	// Area 5
	register_sidebar( array (
		'name' => 'Third Footer Widget Area',
		'id' => 'third-footer-widget-area',
		'description' => __('The third footer widget area' , 'twentyten'),
		'before_widget' => '<li id="%1$s" class="widget-container %2$s">',
		'after_widget' => "</li>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

	// Area 6
	register_sidebar( array (
		'name' => 'Fourth Footer Widget Area',
		'id' => 'fourth-footer-widget-area',
		'description' => __('The fourth footer widget area' , 'twentyten'),
		'before_widget' => '<li id="%1$s" class="widget-container %2$s">',
		'after_widget' => "</li>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

} // end theme_widgets_init



// Add all the groovy widget areas
add_action( 'init', 'theme_widgets_init' );