what do you guys think of this UV air purifier?
http://www.germguardian.com/prod_uvcair.asp

is this thing really work? I want to get it for air purifier.

Interesting. UV light does make a good killer.

I agree with UV is a good way to kill types of bacteria but like Izzy said it has to move air through it for it to work, plus it has to be efficient enough to expose the particles to the UV light before it leaves the source. The longer you expose the volume of air to UV the more it kills. So I would think they would have a slow movement fan to slowly move the UV light over a fan to expose it for the time enough to kill everything or use stronger bulbs that bombard it at a given rate. I don't have much experience with these devices but I see them in restaurants and hospitals. The theory sounds like it should work.