I third the rec for Dr. Bershel. She's been our ped for three years and is very laid-back, very reassuring. We did extended breastfeeding (2.5 years), co-sleeping in the bed, etc. I'm pretty strongly pro vaccines, so I don't know her opinion on the vaccine thing, but she's often suggested alternative therapies.

What's more, on our first visit, she wrote down her cell number and handed it to us and said, "If it's the middle of the night and you can't get ahold of the on-call doctor or if you're worried about something, call me. Any time. If I wanted to sleep, I wouldn't be a pediatrician."

She is the best.

I'll also second the Somerville Moms list on Yahoo. It's a great resource and a nice mix of opinions.