One day a year, in cities throughout the country, parking spots take on a whole new meaning. Simply by paying the parking meter and rolling out some grass, residents claim these spaces as public parks—and have their say about how small but precious pieces of urban real estate are used.
Source: http://www.yesmagazine.org/

A park in front of Ritual Coffee Roasters in San Francisco. Photo by Scott Beale / laughingsquid.com

Rebar's PARKcycle—a human-powered, moving park—was built for the 2007 event in collaboration with sculptor Reuben Margolin.

A Scrabble game played at one PARK(ing) Day spot in New York City in 2008. The temporary Staycation Park, at the corner of Court Street and Atlantic Avenue was one of 50 spots in the city. Photo by Linus Gelber.

A lending library park created at Market and Duboce in San Francisco in 2007. Photo by Lawrence Cuevas.