From Dave Brook:
Thanks for your DC issue. I thought you might be interested in these guys.

PARK(ing) is an investigation into reprogramming a typical unit of private vehicular space by leasing a metered parking spot for public recreational activity. We identified a site in an area of downtown San Francisco that is underserved by public outdoor space and is in an ideal, sunny location between the hours of noon and 2 p.m. There we installed a small, temporary public park that provided nature, seating, and shade. … By our calculations, we provided an additional 24,000 square-foot-minutes of public open space that Wednesday afternoon.

They produced a fun video