This example shows a footer which will be at the bottom of the page even if the content does not fill the window's height. When the content reaches to the bottom of the page the footer will continue to appear under the content.
Resize the window to see the footer move up and down, and it won't overlap this content area.
View the source to see the underlying CSS and HTML code.
Read the footer example using HTML and CSS tutorial on Chris Hope's Electric Toolbox LAMP blog for more info and browser compatibilty etc.