This would be a great addition to your themes. I noticed it most recently with Fusion, that if I have a page without a ton of content on it, the footer rises up and sits halfway down the page. Which looks really bad.
If this was built right in, that'd be great. Without the need to go and fix it every time there's an update.
http://www.cssstickyfooter.com/using-sticky-footer-code.html
