yep, that was the idea. (Well, that, and I'm hoping that once Ruby hackers try Haskell, they'll be forever corrupted by the Functional side of the force.)
I used to be pretty slack about it, but then started working in a non-startup environment where it's the only possible way to protect your code from random external breakages. I wouldn't code without unit testing even on my own stuff now, and ideally I'd have continuous integration if I'm working with even one other person.
With the current primitives, it'd be pretty hard to do. You can get a list of your friends, but you can't do get a list of their friends - the best you can do is ask if two people are connected. you'd basically have to keep an offline list of the facebook web of connections.