Lifehacker takes on a comparison of two of the major disk encryption systems available and puts them in a bloodthirsty cage match. OK, maybe not quite.... however, the OS Encryption Showdown: Vista's BitLocker vs. Mac's FileVault is a good primer as to what's available and the up and downsides. Read the article to see who wins!
I'm disappointed that Linux doesn't have an offering here. Actually, I'm disappointed Linux doesn't have a user friendly offering here. Linux has had disk encryption for a while now, it just hasn't had the friendly frontend that OS/X and Vista have put on it, and instead make the user resort to typing in cryptic commands like dd and cryptsetup and dealing with terms like 'loop-AES' and 'LUKS'.