Chameleon Images... a suggested use for the blue channel

GasHed

So, I was messing around with some Chameleon buttons and had trouble getting them to look 3D. I had the thought that it would be nice if the blue channel was tied to the brightness (i.e. Hue, Sat., and Bright.) so that shadows could be easily added to the buttons to give them a 3Dish look. Or... does there already exist an easy way to do this? I tried bleeding the border into the body of the button, but unless the border is a dark color, this doesn't work well.

Pat