The Voyager is the joint-cheapest 4GB flash drive in the group and it costs a reasonable £4.81 per gigabyte. The outer casing is rubber and should absorb any bumps or shocks. Unfortunately, there's nowhere to stow the rubber cap when detached.
Corsair's Voyager was the second-fastest drive in our photo files test, and produced respectable speeds in all others. It's a great choice if you need something durable and inexpensive.