Well, they aren't free, but Cryptomite and Foldershield from Baxbex software -
http://www.baxbex.com/cryptomite.html - look nice and I've used some of their other software which is quality stuff.
Edited to say - if you just want to protect things from prying eyes you can use the encryption module in WinZip - it isn't very secure but it may be enough for you. Not everything needs DES standard encryption y'know.