Personal UV Meters

Before getting into the sunscreens. Sunscreen week kicks off with information about a cool little gadget. check out this Oregon Scientific Personal UV Monitor. It also has an exposure timer. Or look at the full list of UV meters available at Amazon.com

The idea of personal UV monitoring intrigues me. I wonder whether it is a useful device or just another gadget that would end up collecting dust?

They certainly seem interesting though! Has anyone out there tried one of these?