Spinning off the other thread, here's a very naïve attempt at something simple to kick things off.

Wikipedia day is next month!

Can there be a simple informal meetup in some library or cafe in Boston on one of the weekends? Saturday January 25 would be ideal for me, but the weekend before that would be okay, too.

Some American cities are already organizing something :)

I can't organize much more myself because I'm not in Boston and I hardly know any places there, but maybe some locals have a good proposal.