In my opinion DC is
not really a Naked bike ride, because there (along with a few others) they arrest anyone 'fully' nude.
To see if you have a ride in your town (in which case, get out your camera instead of waiting for someone else to do it!) see this website....
http://www.worldnakedbikeride.org/
There are hundreds of them, mostly on the weekend of
13/14th June.