Great encryption software, although there is no full disk encryption for the Mac from TrueCrypt I hope to see it eventually. By the way, I didn’t mention this yet: it’s free.
http://www.truecrypt.org/
UPDATE: While TrueCrypt does not do full disk encryption (FDE) for the boot volume still, it does do FDE for other volumes fairly easily and of course free. If you need FDE for boot volumes on Mac OS X check out PGP and CheckPoint FDE. PGP Desktop is easy to install and use and has a great command line interface. CheckPoint though seems to be a bit more mature and has an easier methodology for mass deployment.
