Urban activists assist cash-strapped cities with seed bombs

The little round balls made of red terra-cotta clay, as police at a World Trade Organization protest a few years back learned, are not bombs. At least, not in the traditional sense. Neighborhood groups and truly "grass-roots" activists around the country are taking back abandoned properties and derelict strips of public lands through little balls made of clay, compost and seeds.

Although the process is great for highway medians, denuded parking strips, industrial areas and vacant lots, the rise in home foreclosures and the general increasing interest in creating lush urban spaces with nutritious plants for bees and other beneficial insects means that local activists could be throwing bombs -- I mean, balls -- in their neighbor's yards, too.