I've been collecting a few over the years.
I've got three 1 gb's. 1 is used for virus stuff because it has a lock feature on it. Another is used for portable ubuntu. And the last is used for nothing.
I've also got a 2 gb. This one i use for school stuff.
And I have a 16 gb, which I use for games. I have portable counterstrike, star craft, every single N64, NES, SNES, and GBA game in rom form, and a few other small games.