New York subway authorities:These are the heights to which street art can ascend when its creators don't fear arrest. Imagine what Poster Boy could do with a canvas this vast.

Perhaps "artistic depths" is a better term than "heights:" German artist Edgar Müller created this miles-deep, 3D visual crevasse for the "Festival of World Culture" in Ireland last year. Video went online just over a week ago, offering Gotham's public arts administrators an idea for a viable, cheap, recession-era alternative to last year's waterfalls.