I've been after a USB powered fan for a while now, and most are cheap and nasty and very loud! This fan is sooo quiet!
Don't expect a gale for wind fro this device, the trade off is a silent fan... Put it on your desk a few feet away from your face and it's great!
The adjustable speed is the winner here... on minimum it's a very sublte breeze and up to high, it's a nice breeze. Anymore powerful would annoy you after a few minutes, this is subtle and effective.