facebook?

To facebook or not to facebook?
That is the question...

I have had a few people tell me I should join, but I have no idea what the flip it really is or how it works. Plus the fact that I feel like I'm too old to do it.
Anyway, is it basically like myspace, where you just have conversations with people so I could still do the blog? And keep in mind, I am not the kind of person who goes out and says please be my friend and thanks for the add (like myspace) so if it's like that, I don't think I want in.

Anyway, just inquiring, anything anybody can answer would be great.
And, another thing, is it going to be so addicting that I won't be able to get anything else done including this blog?

edited: just found this blog post, and yes it answered many questions. But I still need to hear from you people...

edited again: I took the plunge. I signed up. Let's see how this goes.