Alter the sharedaddy box title.

functions.php

<?php 
//* do not include php tags

add_filter( 'sharedaddy_box_title', 'custom_sharedaddy_box_title', 10, 2 );
/**
 * Callback for RFMeier-Genesis 'sharedaddy_box_title' filter.
 * 
 * Alter the sharedaddy box title.
 * 
 * @since 0.2
 * @author Ryan Meier <rfmeier@gmail.com>
 * 
 * @param string $title The current sharedaddy box title
 * @param object $post The current post object within the loop
 * @return string $title The current sharedaddy box title
 */
function custom_sharedaddy_box_title( $title, $post ){
    
    //* use modular arthimetic
    $rem = $post->ID % 3;
    
    //* determine the title by the remainder
    switch ( $rem ) {
        
        case 1:
            $title = __( 'Share it! Share it good!' );
            break;
        
        case 2:
            $title = __( 'Share this with the world.' );
            break;
        
        default:
            break;
        
    }
    
    return $title;
    
}