Where can I go to play with dogs in the Boston, MA area?

Where I live in Boston, I see so many adorable dogs being walked all the time on the street. That however, is not necessarily the best place to approach dogs- or people. I'm originally from the Midwest, and we have PetCos and Petsmart that have puppy petting all the time. Is there a friendly pet store in or around the Boston area that lets people come in to play with dogs? I have a friend who is absolutely obsessed with dogs and taking her to a pet store/place like that would be a great present for her. Thanks for your help!