Facebook's iPhone app has been updated to version 3.2 and, among other things, brings support for the new Places service that lets you see where your friends are and what location-based social activities they're up to. (At least in the US, when I tried it it said it wasn't yet available in my region.)
What else is new?
Places will also offer integration with existing location-based apps like Gowalla.
If you've tried it out, let us know how Facebook places is working for you on your iPhone...
Update 2: And here's Facebook 3.2.1 with bug fixes.
[iTunes link, thanks to everyone who sent this in!]