i have a 16MB one around that i use on occasion. and its the size of a tank! (in memory stick terms)
however i usually use my 512 (no need for bigger it turns out)
The smallest USB stick I've had was 32MB. It lived for roughly 5 years before it broke, but hey, it was free. Off topic a little bit, the smallest hard drive that I've had and that I still have and still works, is an old Maxtor 256MB drive :biggrin:
Smallest I ever had was 4GB; before that I used DVDs and Floppies.
Smallest HDD I've got atm is a 40MB (yah, megabyte) that's in my attic in an old Win 95 comp - but I must have had a smaller one in my old Win 3.1 pc, but that was thrown away when I went on holiday Evil parents clearing up.