I just picked up a few of these super-tiny USB drives as gifts for US$14.50 for 2 gigs it's a heck of a deal, the ones that are smaller than a VERY small stick of gum.
As one of the reviewers on Amazon said: "[If you were] carrying top secret KGB documents on this drive, you could easily swallow it and recover it later with little or no discomfort."
Personally, I've got an OCZ Mini-Kart, but this one is about 40% smaller. When will it end? How much smaller could this possibly be? Probably just the metal contacts by themselves.
The Mini-Kart has been a very good little drive, if a bit slow. The Sony MicroVault is well -thought off also, and is fast enough for ReadyBoost. The KingMax is now available up to 4gb and is also wicked small. Atwood likes the Transcend, but they are a little slow also.
Here's the lineup:
Be sure to encrypt your drives if you store anything sensitive on them! I discussed this and TrueCrypt in my 2006 New Year's Resolution Post.