// Custom Excerpt length

remove_filter( 'excerpt_length', 'twentyten_excerpt_length' );

function finest_excerpt_length( $length ) {
    return 20;
}
add_filter( 'excerpt_length', 'finest_excerpt_length', 999 );

/**
 * Returns a "Continue Reading" link for excerpts
 *
 * @since Twenty Ten 1.0
 * @return string "Continue Reading" link
 */
function twentyten_continue_reading_link() {
    return ' <a href="'. get_permalink() . '">' . __( 'Continue reading', 'twentyten' ) . '</a>';
}

/**
 * Replaces "[...]" (appended to automatically generated excerpts) with an ellipsis and twentyten_continue_reading_link().
 *
 * To override this in a child theme, remove the filter and add your own
 * function tied to the excerpt_more filter hook.
 *
 * @since Twenty Ten 1.0
 * @return string An ellipsis
 */
function twentyten_auto_excerpt_more( $more ) {
    return ' &hellip;' . twentyten_continue_reading_link();
}
add_filter( 'excerpt_more', 'twentyten_auto_excerpt_more' );

/**
 * Adds a pretty "Continue Reading" link to custom post excerpts.
 *
 * To override this link in a child theme, remove the filter and add your own
 * function tied to the get_the_excerpt filter hook.
 *
 * @since Twenty Ten 1.0
 * @return string Excerpt with a pretty "Continue Reading" link
 */
function twentyten_custom_excerpt_more( $output ) {
    if ( has_excerpt() && ! is_attachment() ) {
        $output .= twentyten_continue_reading_link();
    }
    return $output;
}
add_filter( 'get_the_excerpt', 'twentyten_custom_excerpt_more' );