A system for playing with walls, Space Invaders 2006 uses a person’s motions to control a video game projected on the facade of a building.

Freecycle.org is a free email subscription service that lets members offer items free to others on their city’s list: the location, quantity, and condition of goods they would otherwise throw out a

A Google Maps “mashup” or add-on program, garbagescout.com lets New Yorkers upload photos of objects on the street, and identify them with descriptive keywords.

Map-generation software that provides users with their “of least surveillance” between two locations in New York City, iSee Manhattan uses data collected by groups such as the New York Civil Libert