I've always been fascinated by graffiti and street art, maybe because I grew up in the SF Bay Area where you see a lot of tags and murals (especially in places like the Mission in SF). I notice that kids' eyes light up whenever they see art on a wall also.
In college I spraypainted the basement of my dorm. I did not do a respectable job in terms of art or lettering, and watching this guy reminds me of the fumes -- which were not good.
But check out the way he layers the lines and shapes, and how he visualizes what he's going to do before he does it. It's really neat.
And, this is super cool too - a Taxonomy of characters used in graffiti in Paris. Click on a word, then click on the red character to see examples of it on the street.
Good graffiti is definitely art, bad graffiti is, well, bad art. Tags with no care or creativity get on my nerves. And irresponsible painting of things that should not be painted stinks, too. It's hard to separate the graffiti form from its roots of course, and I'm not sure that's what's desirable. But it would be nice to hit a middle path where the art can be developed and appreciated minus the class and culture baggage. Yeah, I'll get right on that. Sigh.