Groups, Clubs, MeetUps, Societies, Chapters

Science for the Public
Mass Audubon Society
Boston Aquarium Society
Massachusetts Butterfly Club
Northeastern Weed Science Society
New England Botanical Club
Center for Naturalism
Parts and Crafts
Nerdnite
Boston Skeptics
GreyThumb Society
Boston Audio Society
Boston Post Mortem
Amateur Telescope Makers of Boston
American Association of Variable Star Observers
Cambridge Entomological Club
Micromounters of New England
Boston Mineral Club
Audio Engineering Society
TechnoFrolics
Society for Risk Analysis
Boston Linux & Unix
Boston DIYbio
Bending Boston
Willoughby & Baltic
nublabs
New England Model Engineering Society
Boston OSGeo Enthusiasts
Tech Model Railroad Club of MIT
The New England Rubbish Deconstruction Society
Computer-Human Interaction SIG
neuphi
Trebuchets
Inventors' Association of New England
Connecticut Antique Machinery Association
New England Games SiG
OrigaMITM
boston2600
American Society for Information Science,   New England Chapter
Human Factors and Ergonomics Society,   New England Chapter
American Society of Materials,   Boston Chapter

Meetups

NerdFun
Life Sciences
Boston Biotech
Inquisitive Minds
H2O Boston: Water & Energy Technology
Boston Astronomy
Inventors Association of New England
Boston Math/Physics Study
Ocean River Wildlife
Boston Alternative Energy Supporters
Boston Robotics
suburban naturalists
Cambridge Semantic Web
Boston Computing Review
OpenStreetMap Boston
Metro Boston WiFi
Inventors Association of New England
Boston Chess Club
Theoretical Computer Science
Boston Israel Cleantech Alliance
New England Women in Biotech
Boston Transhumanists
Mass Aerospace Council
Mathematics & Logic Puzzle Lovers
Creative Mathematicians
Boston Sci-Fi/Fantasy
Boston Digital Arts

IEEE Chapters

Computer Society
Robotics and Automation
Lasers & Electro-Optical
Social Implications of Technology