Here's some other things I've collected during my time living here that have been helpful:
In this event, you meet in a large group setting, and pair up for 5-10 minutes to get to know each other. The idea is in the name -- you have prompt cards that "skip the small talk" by diving into deeper questions right away. They have both speed-friending and speed-dating events in Boston, Cambridge, and Somerville.
I've been to a few of these events, and I've always had a good time (or at least have come away with a good story). It can be a little weird diving-deep at first, but also very insightful. This is the kind of thing you get out of it what you put in.
The premise is simple -- take a survey, and get grouped with 5 strangers to have dinner with. You meet up, and the app provides questions to keep the conversation going. If it goes well, multiple dinners can meet up for a drink afterwards. I personally haven't been, but I know people who have gone, and I've heard good things.