Fly Cab—one of several arty remixes of live Yellow Cab GPS data brought to you by the Exploratorium's Cabspotting project—and it delivers. Against a night-black background, the bright dot of a randomly selected taxi retravels its previous five days' trajectory in less than four minutes, leaving a white, spidery trail behind it as it climbs through time. The line builds layer upon 3-D layer of repeated trips—dense downtown squiggles, arcing straight shots out to SFO and back—until a lovely lacework tower of abstraction rises glittering in the darkness. Who knew the pleasures of 21st-century techno-surveillance could be so purely, so innocently aesthetic?

Not that innocence is ever guaranteed with this sort of thing. Cabspotting's organizers are quick to assure that no individual privacy rights were harmed in the making of this project, but their language otherwise flirts racily with fantasies of total information awareness. The map traced daily by the Yellow Cab fleet, they write, "hints at economic, social, and cultural trends that are otherwise invisible." But it turns out you need more than hints to see the civic realities embedded in these maps. Amy Balkin's "In Transit" shoehorns facts about taxi driver homicides and no-go neighborhoods into her project, coaxing the GPS data to speak its truths, but in fact the most eloquent maps here are the ones that—like Apodaca's, or like the time-lapse overviews that show the traffic network pulsing like arteries—have nothing much to say. Sometimes knowing the meanings behind the patterns of the everyday isn't half as meaningful as knowing there's a pattern there at all.