I certainly don't know much about setting up a user's group per se, but I am thinking that the city's municipal building has function rooms available often. What do you think the turnout for something like that would be? And what would the "agenda" be?
Given that Radio Shack now retails Arduino, and I know several folks who are about to be introduced, it's only going to increase the demand for a user's group, particularly for hands on help from experienced folks to new users and that kind of thing.
I'll think about this over the holidays,keep the thread alive with any thoughts you have on this. Marlborough (where I live) is pretty central to Massachusetts, and is four miles from the intersection of Interstate 495 and 90. Come to think of it, let me ask some old friends from DEC now over at the Mill. There's full unused labs over there.. that's Maynard, a little more off the beaten path, but Intel might just be willing to subsidize this type of thing... Only thing is, that's Intel's plant now, they might get twitchy about our infatuation with our little Atmels!