I'm co-founder of www.airbnb.com, a website that let's you find locals with whom you can stay while spending less money and having more fun. Our coverage in Boston right now is relatively sparse, but there are some places you might like.
Here's one: http://www.airbnb.com/airbeds/show/1130?nights=2&lng=-71...
You can sort by distance, price, recommended, etc.