If you have a few minutes, I hope you'll have a look at this video on the TED blog. J.R. is a Parisian artist whose canvas is life, whose gallery is the world. (J.R. is the recipient of the 2011 TED prize.) To my mind, his art is about the transformative power of graffiti when graffiti is at its finest--which is to say raw, honest, open, and very big.
Watch this, please. It'll make you feel good.