Green Roofs
I was absolutely delighted when the local indepedent newspaper, Independent Weekly, ran a feature about green roofing. (Wikipedia defines it: A green roof is a roof of a building which is partially or completely covered with plants.)
The Indy’s story is here: Raising the (green) roof: Green roofs are the new black tar.
Some benefits of green roofs: natural insulation against heat and cold, helping treat air pollution, reducing storm water run off, providing food for people (depending on your plant choice) and providing a habitat for wildlife.
More resources about green roofs:
Green Roofs for Healthy Cities
American Society of Landscape Architects
I forgot one more benefit of green roofs: They look cool!