When we moved to a new city, I joined a local community center. Had a gym, swimming pool and I took aquafit which helped me meet a lot of people with similar interests. You could also take classes in thing that interest you such as cooking classes, fitness, or whatever the case may be.
There are lots of great forums here, but as Heather said, people are from all over the place. I can tell you though, I met another member of here that turned out to live only 20 minutes from me and we are really good friends in real life as well, so you never know!
Join a church by all means. You're not supposed to throw your own shower anyway, so unless someone else offers, you'll be SOL for a shower. The more people you know by the time you're in your 5th or 6th month, the more likely someone is to offer. :)
The pregnancy forum is great and so is the ttc group but it has people from all over the globe!
I suggest that you should go to your local library and see what kind of groups or classes they offer to make some friends in your area. When you are pregnant I'm sure there will be many groups or things that you can join.