I have been on Facebook for about 4 months now. I have reconnected with many old friends from school, drum and bugle corps. (some of the best years of my life!), and from earlier jobs.
We have a family "connection" group whereby anyone with our family name can join, and as a result, I have connected with many relatives with my family name, including a cousin who lives in Italy! We have traced how we are related and are putting together a family tree. My cousin in Italy is planning to travel to Avellino in the summer to do more research (a 5 hour drive for him), where my great grandparents (and his family members) were from.
So, for me, it's been great. I'm not addicted ... if I was, I wouldn't be here!