Using the techniques from the mouseover tutorial, combined with Java Script II, I created a few example effects that can be acheived. Just pass your mouse over each of the below images to see the different effects:

These effects were created using some of the filters and options contained in Photo Impact. But you could easily accomplish the same thing using most any graphic editing or image manipulation program.

Again, the key is to create 2 images. The "before" or "off" image and the "after" or "on"' image. Then run them through Java Script II for some fun results.