I went to meetings without a having a sponsor and without working the steps. I went back out and drank. Now I have a sponsor, I'm working the steps, and for the first time in 3 years, I've been able to put together 90+ days of sobriety. I guess that kind of speaks for itself.
Oh, and as far as seeing someone you know ... I live in a small resort town of less than 10,000 people and I had the same fear. Just remember, even if you DO see someone you know in the rooms, they are there for the same reason you are.