How to keep footers at the bottom of the page with CSS

http://matthewjamestaylor.com/blog/keeping-footers-at-the-bottom-of-the-page
This is a site I found that used strictly table-less HTML and CSS to position the footer at the bottom of the page even when there’s littile or no content. I tested it in IE6 & 7, Firefox, and Opera and it worked fine in all 4 browsers.