Julian Dibbell writes,

OK, you’re hip, but face it: Hasidic Jews are hipper. They moved to Williamsburg before you did, they were into Kabbalah before Madonnawas, and—as artist Elliot Malkin’s eRuv: A Street History in Semacode makes elegantly clear—athey were master map hackers at least a century before Google Maps opened its code and made 2005 the most happening year in cartography since, oh, 1492.
eRuv’s hero is Rabbi Yehoshua Siegel, who in 1907 used a pretty cool map hack to free Lower East Side Hasidim from strict rules against carrying objects outdoors on Sabbath. Siegel declared the entire East Side a single private residence, in effect, bounded by an eruv—or symbolic “wall”—made up of waterfront on three sides and, on the fourth, “a door frame like none other”: the Third Avenue elevated train. The el closed in 1955, but Malkin has brought the old eruv back to ghostly life, plastering the former train route with camera-readable barcode links to his site. Point and shoot your Web-ready phone cam at an eRuv sticker in Chinatown, say, and thephone will fetch you local maps and images from the days when the el defined an urban reality both physical and ritual.
“Psychogeography,” the Situationists called it: a counterofficial mapping of the urban landscape, attuned to its effects on hearts, minds, and habits. In Situationism’s 1960s heyday, aimless strolling was both the means and product of research, actual maps in those days being too static. But the recent explosion of Google Maps hacks—from narrow obsessions like the Where’s Wilco tour map to communal atlases like Tagzania—suggests a proper psychocartography may now be at hand. Failing that, it proves at least that the Internet is finally catching up with the Talmud in its cartographic sophistication, moving on from maps that give directions to maps that, at last, also take them.

Source.