Commuting for me has also been the basis of training and conditioning for charity centuries and, more recently, randoneering. I have a commute that is 14 miles one way, which usually puts me at home by 8pm, so no evening group rides for me. However, I will also do solo training centuries on weekends when I'm not doing brevets.

Though, given the recent string of good local weather, and number of cyclists emerging from winter hibernation, lately evenings on the bike path basically become impromptu group rides. Last night's commute home involved me pulling a pace line of bikes about six miles through Lexington and Arlington, MA at about 22 mph. I imagine that a bike with panniers can be fun to draft.