• BetaHouse
  BetaHouse is a coworking community in Central Square, Cambridge, MA for entrepreneurs, technologists, creatives, makers and independents. The cost to join is $225-$375/month.
• C3 @ Cambridge Innovation Center
  C3 is brought to you by Cambridge Innovation Center. Located in the light-filled 10th floor of One Broadway in Kendall Square, Cambridge it has its own, unique feel and independent facility and services. The cost to join C3 is $250 per month.
• DogPatch Labs
  Created by Polaris Venture Partners to connect entrepreneurs and help founders conceive and launch startups. Offers desk space, bandwidth, and coffee to aspiring entrepreneurs.
• Workbar
  Located in the heart of Boston & steps away from South Station. They offer professional and comfortable work space whether you are looking for your own personal desk or just need a place to work a few days a week.
• Tech Super Powers
  The Digital Lounge is a unique space where the digitally-dependent can find essential services centrally located in Boston’s Back Bay.
• Geek Offices
  Locations in Inman Square – Cambridge, Waltham and Framingham. Comes with conference rooms, wifi, lounge, etc. The cost to join is $120-$400/month
• The Brickyard Collaboration Space
  on Sherman St in Cambridge, between Davis Sq, and Fresh Pond, not far from Porter Square. Rental fees start at $300/month.

Sources:
* Don Dodge – Link
* TiE Leadership Program Blog