After some clicks on the net I found out that this NYer makes very nice gallery paintings as well.
Dan's thought on practising both diciplines as follows:
"For me, it wouldn't make sense to bring my street art into galleries. Even photographs of street art to me look kind of uncomfortable. It looks like it's been tamed or housebroken. With street art, I get to run through a thousand ideas a year. Usually, with my gallery work, I keep to one line of inquiry. Being an artist you have all these ideas and there's never enough time. It's frustrating. Street art lets me release all the frustration and pent-up ideas. I can experiment on the street; I can make mistakes and try different techniques. If it doesn't work, it doesn't matter."
I find it really cool that he expresses his creative energy in such a versitile fashion. And along the way, he makes me smile too. Great.