A Couple of events of note:
Sunday night is the annual Halloween ride, meets up at Green street station in JP. I went last year, and it was pretty incredible. Some people had spent a LOT of time on their costumes, but you can go even without. A rolling street party, closer to critical mass than a tweed ride, and a lot of fun. Best if you can go with a group I think- I lost my group immediately, and I had a great time even by myself, but having a posse would make it more fun.
Tomorrow night Oct 27 is a "community walk" with the city planners to discuss the upcoming changes to the Western Ave corridor: more information on the plan and the walk here
This will be followed up by a public meeting Nov 3rd at 7pm at the Cambridge Senior Center in Central square. I'll confess that I haven't been as dialed into the Western Ave reconstruction as much as the bridges, mostly because I trust the Cambridge city planners to be progressive about cyclist accommodation, but after some of the snafus at the Main-Broadway reconstruction I'm not so sanguine, and want to check it out in person.