Now if they'd only make a USB shell/adapter that accepts standard flash memory, like SD or CF. You could carry a dozen little SD cards, and use the same adapter for each.
That was the original Cruzer, but it's not USB 2.0. I've got one, and do exactly that... switch SD cards in and out. A bit fatter, but that's due to the card size of course. You can currently find them on clearance at a lot of Best Buys for 19.99 for the 128MB.