Logging into Facebook to check up on my old college roommate yesterday, I noticed there was a giant message telling me to use Facebook Mobile. Technically, Facebook has had basic mobile features for quite some time (looking at your profile, reading messages), but my friends and I never bothered to use them, specifically because of their lack of support for my carrier T-Mobile. What is new is their mobile tab, which gives you live previews of what different parts of the site will look like on your device. There's also a Fire feature that lets you "set fire" to one of your friends. This won't send them into friend purgatory, rather it sends them a neat status message. It's the equivalent of poking them, and is another useless but amusing Facebook feature for saying hi to people you know in a peculiar way.
I have a few buddies who will get a kick out of the new mobile tab and the firing feature, and I'm sure most twentysomethings with smart phones and corporate data plans will be taking advantage of the mobile interface now that Facebook is actually advertising it. That is, at least until everyone and their brother gets an Apple iPhone in June.