USB Hard drive password protector?

[Stevesoura]

I got my new haddrive for my T42 a couple of days ago. So the Oem hard drive was a back-up. I bought a external exclosure for the 40gb hdd. I was wondering if there was a easy password software protection I can use for the usb hdd. It so easy to get in, plug and play. I would like to feel a little secure at least with a password protector.