My Sandisk Cruzer Titanium came with CruzerLock2 - 448 bit AES/Blowfish encryption. I must admit I rarely use it. Right now I have a few hundred MB of ripped MP3's on it - not quite critical information. Anything important I usually erase as soon as it's moved.
It looks like the basic version, just encrypting data on the drive itself, is free -
http://www.sandisk.com/retail/cruzer-cruzerlock2.asp