from their version history notes:

• Full support for Windows 7.
• Full support for Mac OS X 10.6 Snow Leopard.
• The ability to configure selected volumes as 'system favorite volumes'.

TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted volume (data storage device).

More information here: http://www.truecrypt.org/docs/?s=version-history

Cheers,
Adrien de Beaupré
Intru-shun.ca Inc.