I selected 3, and now I must defend myself:
Okay, I have a myspace ACCOUNT, but do not have a myspace. My brother uses Myspace to post his pictures and videos, hes in France at the moment... so calling him is a little bit difficult.
I use Blogger (through my Google account) but not often at all, specifically since I started my own blogsite.
I now use my own blog system, and site. Actually, its a computer in my basement... sitting, waiting for incoming Port 80 requests from my friends... This is, if it works right (Linux is proving itself evil at the moment), what I will use as a primary social network type site. (Of course, I dont feel like being tracked down... so I wont publicly share the address until I am sure the server is secured.)