What do you keep on your USB flash drive? We only really keep it stocked with copies of whatever projects we're working on at the moment. In the life of a blogger, it's certainly not anything too interesting. But if your line of work is more in line with 007, then you might want to pick up the IronKey.
The IronKey, which holds 4 GB and is waterproof, was developed specifically for the US Military, and includes a hardware encryption chip that actually scrambles all the data on the thumb drive if you don't enter the proper password when you plug it in. Normally, the concern of your password being hacked would arise, but after 10 incorrect password attempts the chip completely self destructs. Any attempts to open the device will also be met with disaster as the device is filled with epoxy to damage the opened thumb drive.
On second thought, we do have something that needs this kind of protection. But if we told you, we'd have to kill you.