Here are a few of the more active groups with Caledon-related events:

Independent State of Caledon (by invite only--ask a resident if they can get you an invitation)

Caledon Oxbridge University Group

Caledon Library

Book and Tankard Pub

Caledon Nights

Caledon Stormhold Neighborhood Assn

Aether Chrononaughts Tiny Steps (Relay for Life team that includes Caledon)