I'm using this on a site I'm building - it's not anything terribly complicated, mainly I was bothered by the way the text on a page looked as it hit the bottom of the browser window, and I wanted to soften it. Came a with a handy technique I've already thought of several uses for -- it's CSS based, positions 10 different DIVs stacked at the bottom of the page, with a z-index higher than the page content. Each is 100% width and only 3-4 pix high, all are empty with white backgrounds.The opacity filters are set so the bottom DIV is 100%, the next highest is 90%, then 80, etc down to 10%.
As the page content slides behind these DIVs, which begin at only 10% white and increase, it makes the content appear to gradually fade away for a much more elegant feel. You can see an example on the (unfinished) site I first used it on here: http://www.asbpe.org/chapters/newcleve/home.html
Nice but it doesn't seem to work in IE6 and if it doesn't work in IE6 anyway, wouldn't it be easier to do with just a simple transparent PNG, fixed to the bottom?