At the SF Concourse Exhibition Center, 635 8th Street (at Brannan). Saturday 10AM-6PM & Sunday 11AM-5PM. Easy access by BART. Lots of ways to get in free. Reduced admission online. Great organic food & biodegradable utensils. Sample & buy wonderful healthy food & goodies at many booths. Lots of kid oriented, fun stuff and a green kid zone. Hear Amy Goodman of Democracy Now! at 1pm on the main stage. Also John Perkins, Jim Hightower, Starhawk and many, many more. Test drive electric cars & bikes, buy organic clothing & housewares, check out the yoga and movement workshops & taste organic wine & beer. The Sierra Club presents short environmental films all day both days. There are music and dance performances. Several stages going at once. For information and tickets go to www. greenamerica.org and globalexchange.org. 18 and under free. Free to union members with card, Sierra Club members, Green America and Global Exchange members and I hear that if you bring 4 cans of food you can get in free. Check that one out.