Flash Drive Encryption + Idle Time Out

[white_devil]

I was wondering if anyone knows of a reasonably-priced way of having an encrypted flash drive that will lock itself after a period of inactivity so that if I leave it in a computer someone won't be able to come along and read the contents. I've looked at Ironkey and it looks to do the job but the price is extremely high. Kingston's DataTraveler Vault Privacy Edition and SafeStick also look like they would work but they seem to require centralized management software and are geared towards large organizations. I'm just looking for something simple for a handful of flash drives for myself.

 

[Mr. Pedantic]

Truecrypt can be set up to auto-dismount volumes after a period of inactivity. Don't know how it plays with hardware encryption, though.