Theo sez, "Pedalpalooza is 2+ weeks of open-source bike rides in Portland, Oregon starting on June 11th and ending June 27th. Rides are created, posted to the calendar, and lead by anyone. One of my rides is the XKCD ride, for which I will be dressed as Cory Doctorow; thought readers might find that funny."
Other rides include: chocolate ride, noobs on unicycles, yoga for cyclists, naked bike ride, surprise bike wedding, homeless hotspots bike tour, tour de goats, old French bikes, pun-ishment ride, trek-tosterone ride, pretty panty ride, dead freeways ride, unimproved road ride, Sisyphean cruller crawl, pedal powered pajama party, etc etc etc.
Pedalpalooza (Thanks, Theo!)