Right around the corner from our new apartment here in Los Angeles is an outdoor greenscreen owned by Sony Studios. Something was being shot there the other night, for instance, complete with what amounted to an artificial moon held by crane at least sixty feet above the rooftops, glowing amidst evening fog like a new installation by Leonid Tishkov.
There's something oddly Holodeck-like about having a greenscreen literally just two buildings away from us—as if at any point we might sneak out into what seems like a derelict parking lot, with some odd props scattered here and there, only to be propelled into bullet-time, the world around us dissolving in a hail of miscomposited imagery.
It's the new urban Baroque! Install greenscreens everywhere in an optical infrastructure for the 21st century—a DIY industry of everyday special effects, little greenscreens popping up beside trees, in alleyways, behind buildings, atop roofs, the entire urban environment camera-ready and pierced like St. Sebastian by the arrows of parallel worlds, our cities become effects labs and every sidewalk a set.
We'll host greenscreen parties, illegal raids on this empty parking lot at midnight to stage the elaborate counterphysics of our unacknowledged parallel lives. 
What, for instance, could Google Street View do with this? Every sixth billboard in Los Angeles chroma-keyed to show a new city laminated atop the existing one, phasing in and out like camouflage and opening strange new optical possibilities for urban design in an age of composite imaging.
