[JeremyR]

Eh, from Wikipedia:

http://en.wikipedia.org/wiki/USB_flash_drive

Flash drives can be defragmented, but this brings little advantage as there is no mechanical head that moves from fragment to fragment. Flash drives often have a large internal sector size, so defragmenting means accessing fewer sectors. Defragmenting shortens the life of the drive by making many unnecessary writes

So I wouldn't.