Davis Sq.

Agree. It's a bit far from downtown but it's on the subway and gives you easy access to the startup community in the Central/Kendall area with better cost of living.

Definitely stay in Cambridge, though. To get cheap living on the Boston side you have to live way out on the Green Line, which will make it a royal pain to get to meetups and other technology events.

I am in Dallas right now wrapping up Tech Wildcatters, but I'll be back in Boston in August. Feel free to email me.

Definitely. I'm a 10 minute walk from Davis and Porter Square, and there are plenty of places for $2,000 / month, w/ 4 bedrooms. Diesel Cafe, in Davis, has plenty of startup people hanging out there on a regular basis. And Viximo and some other startups have office space around here.

You're right on the red line, so it's easy to get out to any of the more active (but more expensive) areas like Harvard Square or Kendall Square (where MIT is + the Cambridge Innovation Center and the upcoming Venture Cafe).

Check out the LJ community: http://community.livejournal.com/davis_square

Central Square has TechStars and several startup offices (e.g. oneforty). Central also has betahouse, the best coworking spot in Cambridge / Boston. And you can find places in Central Square that are similarly cheap. But Central Square is probably a bit less safe.

Absolutely, or as much of a walk as you like from it (e.g. Ball Square was fine for me). And the point about living on the other side on the Green Line is spot on, I did that for a couple of years and really regretted it (and then moved to Davis Square and stayed there or a bit beyond until I left the area).