Well, now the West Coast has gotten the same treatment. Shells descended on Los Angeles and put up 45 rap quotes. (I feel like Warren G.'s "Regulate" alone could provide enough material for the whole project.)
If you're in L.A. and want to check it out, you're out of luck. According to a Los Angeles Times story last week, every sign has been stolen. (Thanks for pointing out, BuboBlog Southern California correspondent Kasey.)
View larger map on latimes.com
I'd still like to see Shells bring this to the Bay Area, though it's hard to imagine there is 45 signs worth of material (at least not without going to Vallejo).