There used to be a weekly polyboston social thingy at a place called diesel café in davis sq somerville. I just googled diesel café poly and got a bunch of hits, including a link to a livejournal page. nothing less than a year old and it doesn't say anything on the diesel café website. But you could start with those articles and i am sure if you called diesel they would probably be able to give you some useful information whether or not they still do that.
I have never gone to it but i heard of it.