Mike Taylor
UK
4.2.8 (Feb 17, 2010)
Defragging USB sticks will break them (see draculla's review) or at the very least shorten their lifespan. Don't EVER do it. The reason: USB are solid state devices, hard disks are magnetic devices. Solid state devices can only write to each cell a limited number of times (50,000 - 1M) before they become stuck - read only. Hard disks being magnetic can be written (millions).
Do NOT defrag USB drives.