That's stark. (Photo: Twitter)

Right now, it's like the literal dark ages downtown. No power, no internet, patches (at best) of cell phone service. People are chronicling the scene in video, narrative and photo form. But if you want to see a really stark visualization, check out this screenshot of Foursquare Explore's trending locations, tweeted earlier by Peter Wu. His comment: "A tale of two cities."

Mr. Wu isn't the only observer to pick up on how the storm sliced the city in half. Last night, the Daily Show devoted an entire segment to riffing on the notion that as the lower half of Manhattan falls apart, uptown is wiling away the hours with Broadway shows and brownies:

Foursquare's Explore for web

Foursquare says recycling your data is good for you. Because when others use information published on Foursquare to find new destinations, that's what C.E.O. Dennis Crowley calls it: "recycling."

Speaking at the Mobile World Congress in Barcelona, Mr. Crowley gave his whimsical take on how Foursquare users can benefit from using the app. He said Foursquare enables the user "to cut through the data stream in a way that no one has done before" and Foursquare's "Explore" service helps the app's 15 million users and 750,000 merchants who have signed on so far form "a big community."

CNET's Roger Cheng reports that Mr. Crowley also used magic to illustrate how that community might interact:

Crowley described the service as the Marauder's Map, a essential tool in the Harry Potter series of novels and movies and a back-end way of calling its service magical.

His goal is to have Foursquare recommendation dots on any map, whether that be on a PC, smartphone, or other GPS system. He believes this online information will drive people to experience the real world.

The Marauder's Map comparison combined with Windows 8's "charms," makes it seem like there's a subtle theme developing in Barcelona. Maybe Foursquare's "Explore" will help users find Bill Gates's horcrux.