I hate to re-post, but this is something I constantly use, and I didn't want to lose it, so I'm throwing it in my blog. Thanks to Chris Coyier of CSS-Tricks for this one (you can read the full post and see a demo on his site).

// Window load event used just in case window height is dependant upon images $(window).bind("load", function() { var footerHeight = 0, footerTop = 0, $footer = $("#footer"); positionFooter(); function positionFooter() { footerHeight = $footer.height(); footerTop = ($(window).scrollTop()+$(window).height()-footerHeight)+"px"; if ( ($(document.body).height()+footerHeight) < $(window).height()) { $footer.css({ position: "absolute" }).animate({ top: footerTop }) } else { $footer.css({ position: "static" }) } } $(window) .scroll(positionFooter) .resize(positionFooter) });