random background

Hello! I am the proud user of Acquia slate and was wondering if I could somehow rotate the background of the front page on a refresh. Would I use a PHP script with a bunch of images in a directory, or can I use gallery2, which I've already set up.

The web addresses are here:

Drupal site: http://www.claudebing.com
Gallery site: http://gallery.claudebing.com

The album "Backgrounds (Rotating)" is the album of images I want to use on the front page. They're already all the same size and dimensions. Any hints?