Courtney A. found this, and I'm going to say it's a must-read.
Even more to the point, I think it's important, as you use Facebook, to do two things:
a. see if you can make it do something beyond the things you typically make it do.
b. ask yourselves some searching question about what this thing is. And then answer them on your blogs. What I mean is: pull back and take an astronaut's view of Facebook. What is that huge presence hanging there in space.