Quick catchup post. On the First Friday of July 2008, the first South London Critical Mass was held. On the way I done some mapping for OSM, finding some unnamed roads. I find Critical Mass useful for learning your way around London (or wherever it is held), as through random route will take you to parts of the city you have never been before.
Some photos (Just noticed that the Geotagging of the last few failed):
Seems that Critical Mass passes by fuel stations awaiting deliveries. 
I wonder how Bird In Bush Road got its name.
You can try some unusual bikes.