The world really needs a secure, free, easy-to-use, cross-platform encryption system. At the most basic, it would allow you to have a USB drive with encrypted contents and be able to access those contents using a passphrase from any computer – Mac, PC, Linux, etc – you happen to use.
Big bonus points if you can run the software without administrative privileges. That’s important, since so many work, public, and borrowed computers will not allow you to install software that requires an admin password.
I pleaded for such a thing back in 2008, but I still don’t think it exists.
truecrypt.
TrueCrypt requires admin privileges to install under Windows XP.
One option is USB drives with hardware-based encryption incorporated into them physically.
Ironkey drives work with Mac, PC, and Linux. They autodelete after too many failed password attempts, and come with Firefox on them.
They aren’t cheap, though.
Try R10Cipher
http://Www.r10cipher.com
Steve