take a look around the forums. there are some good experienced posts. this knowledge may give you want you need to purchase.
personally, comp usa had an internet ad special on the san disk 256megs mini cruzer for $50 (nice i thought). i decided to get this for school. to say the least it has been a good performer (even though better ones do exist and more costly) and very convienant form of storage.
one thing to note about the filesystem. always use fat with a flash drive. it is the fastest and the accessibility is on all os's that read fat and have usb mass drive support-mac os, linux, win 9x, win 2000, win xp, etc..