The fertile minds at Eyebeam conclude their Feedback eco-exhibition with a green focus on NYC's gray areas. Natalie Jeremijenko stages a noPARK action, creating mossy mayhem in Chelsea's concrete jungle, one vacant spot at a time. Leah Gauthier leads a "sow-in," providing mini-planters to those interested in putting their green thumbs to the test. Brooke Singer, Michael Heimbinder, and Emily Gallagher give virtual-tours of some toxic sites close to home, with views of contaminated Greenpoint and a workshop on identifying local exposure. The closing reception's drinks should take the edge off seeing your block on the Superfund list.