Portable park.

Fear they're paving over paradise? Halifax architecture student David Gallaugher created this grass-lined wheel to "simulate an eternal lawn environment and to draw attention to what he considers a North American obsession with manicured lawns." [via]

And in comments, Duich McKay points out that Glasgow's John Gilbert Architects created its own temporary park in a parking space, in homage to Rebar's park(ing) and in honor of 2006 Architecture Week.