Hi there. I live in the Peterborough area but my girls are much older than your baby. The family center www.thefamilycenter.us/ in Peterborough has some really great classes. I would look into that. I also met some really nice people through Kindermusik in Peterborough. It is a little pricey but nice.
I have a six month old daughter and live in the Peterborough area. I was thinking of going to the Monadnock Hospital mother's group, but have heard mixed things about it, and didn't think I would meet anyone with similar (alternative) parenting styles. I have also considered the baby classes at Sophia's Hearth in Keene but just haven't gotten around to looking into them. I would definitely be interested in a play-date though my daughter is just beginning to "play".