Well I'm going to have to try one. I believe that most of the UV your skin sees is from the blue sky, not directly from the sun. So something with full coverage like that makes sense. It just looks kind of "alien" somehow. Or maybe like people are channeling their favorite superhero, sans cape.
But if they work well that's the most important thing, not how fashionable they are. And in any case they look way better than some of those hats (like that dorky one Ravi linked to). :o)
