Most of the meetings I attend are open discussion, 10 to 20 people. My meetings are quite informal, perhaps half the people share at any given meeting. Occasionally, if no one is sharing, the chair will go around the room for comments. Many will just state their name, "I'm an alcoholic", and pass. There is no requirement to share and I think it is respected that many members are there to learn & listen. Whenever you are ready - or you may just feel inspired one day.
I agree with Anna about going early and leaving late. Someone usually starts chatting with you. You can lend a hand setting up or cleaning up. Looking back, this is where I got to know some of the other members a bit better. A good icebreaker is to tell someone that you appreciated what they said and can relate to it.
Another idea is to try and go to the same meetings consistently. There are Friday night and Saturday afternoon meetings that I go to regularly. I see the same people, get more comfortable with them. Now, I actually look forward to seeing them. We kind of make sure that everyone is doing all right.
And like dgillz stated, your hobbies and activities may eventually start involving your friends & acquaintances from AA. I have plans to take some people fishing later on in the summer.
It was tough for me in the beginning. I did feel like I was outside looking in but like so many other things, this was really in my head. There is a kind of bond among alcoholics that seems to cut through our differences.
Keep at it! It will happen.