First, inspired by judging a citywide bike rack design competition, he paid to have 9 Keith Haring-esque bike racks installed around New York, each an original design by, well, David Byrne. Now he's organized an exhibition of bikes created by artists other than himself, opening Oct. 4 in Connecticut.
And with a memoir-cum-philosophical tome, "Bicycle Diaries," coming out next week, he's penned an article in the Wall Street Journal summing up his vision for ideal urban planning: medium-sized cities, with human-scale construction, wide boulevards, mixed-use neighborhoods, and ample public spaces. His ideas are nothing new, but as with Bono and Africa, perhaps his celebrity glow can rub off on his cause: better cities for everyone. And if that's not sustainable, what is?