In London, Paul Curtis, aka Moose, uses soap and water to create art out of the grime left by progress. He's taking a bit of heat from critics who say he's selling out by throwing up logos for X-Box and TV shows. Maybe he is.
Listen to the NPR story here. There's more at Moose's website here.
And there's actual moose graffiti at this site from Sweden. Believe it.
Plenty of dirt in Taiwan.