Excluding web forums, the only social networking site that I have an account on is LinkedIn. Most of my network (90%) is company/trade/business related - ie: IBM SAN storage content.
That being said, I really don't understand the appeal of all these myspace/facebook/tweety...etc sites. And blogs? Aren't they just someone account in great dramatic detail the day to day events of their miserable existence?
Do I really want to read about someone else's pathetic life? No, not at all.
It's bad enough I know too much about you guys here on Pelican! 
Sometimes, life is better when it is lived 'off the grid.'
Side note: when I come home from work, about a block away from my house, typically there are two boys that are outside playing ball. Kudos to them and their parents for making interaction in the real world a priority! Sadly, most kids these days are too busy updating their facebook/tweety/whatever blogs to bother with kicking the ball around with the neighbor's kid. Sad thing, really.
Ok, I'll get off my soapbox now -- this is starting to sound too much like a blog!
-Z-man.