If you are going to use the drive in a multi-OS environment, then you can:
Get a multi-platform hardware-encryption capable drive (expensive).
Get a multi-platform portable software-encryption application. I think TrueCrypt has a portable version, so you can make a big encrypted container in the drive and leave a small place for the TrueCrypt portable executable. I am not sure, as I dropped Truecrypt for dm-crypt long time ago :-)
Pretending softwarless encryption without hardware integrated cryptography goes nowhere.
Last edited by BlackRider; 09-19-2012 at 12:10 PM.