Cambridge Barter Group Members or Organizers for Historical Feature

Barter groups in Cambridge? I'm working on a piece about the history of bartering groups in Cambridge based on information I've found about a coop during the Great Depression where people went to exchange goods and services. I'm wondering whether something similar exists in Cambridge today (I expect it does)? I know folks engage in bartering on an informal basis, but is there a group that does this in a larger, organized way? If you know of one and/or participate, I'd love to talk with you!