There is a product that glows in the dark. http://www.wemakerocks.com/. I've seen some pictures on the web and these look amazing at night.
Anyone ever seen or used this in a pool? The owner says that he has a pool builder in AZ who orders about 300 lbs at a time making me think there are a few pools in AZ using this product. Apparently, the application is the same as using abalone shells except you only see the product after dark.