I must say, despite all my hatred toward the service, these two security features are rather promising:
1) Temporary Passwords for use in less-than-secure situations where you password might be picked up by someone. Of course it means providing Facebook with your cell number ahead of time. This might be dangerous. SPAM via Text Messaging is on the rise and I for one still don’t trust Facebook to be all that protective of things like my phone number. Generally an SMS-enabled phone number isn’t something I like to give out.
2) Remote Log-Out. I wouldn’t get too much use from this since I don’t use public computers or friends’ computers for this sort of thing… but the notion that I can log myself out remotely if i forget to sign-out on a different computer is pretty cool.