Street artist Evol paints little apartment buildings on utility boxes, concrete blocks, park walls, and art installations (completed, but nothing lasts forever). More on his Flickr collection, or you can see highlights on Twisted Sifter.
As happens all over the world regularly, one night a team of artists got together to paint some art on the sides of trains. This group, however, used their naked bodies... and a fire extinguisher. (SLVimeo, NSFW, via Common Folk Collective.)
Kerfuffle in the LA Art Scene- the possibility that both the mural and its whitewashing are the art - from artist Mario Muller's Truffle Hunting
Biggest 3D street painting ever. As part of the 2007 Moose Jaw Prairie Arts Festival, German painter Edgar Müller and a team of artists turned River Street into, well, a river. Müller and his associate Manfred Stader have done other interesting trompe-l'oiel works around the world.