The debate over genetically modified organisms (and the seeming desire of companies like Monsanto to continue monkeying with the innards of plants) makes one thing clear: If you want to guarantee those pristine heirloom seeds are passed on, you're going to have to hand them over yourself. Raid your garden for goodies and bring them to the Bay Area Seed Interchange Library's Annual Seed Swap, at which a gang of local gardeners and growers gathers to exchange information on ensuring the continued heterogeneity of regional seed stock -- trust us, that mouthful means healthier crops and more verdant gardens for all. Even those without samples to share are welcome; you'll still leave with a little envelope full of potential plants and plenty of new knowledge. Think green starting at 6:30 p.m. at the Ecology Center, 2530 San Pablo (at Dwight), Berkeley. Admission is free; call (510) 548-2220 or visit www.ecologycenter.org.
-- Joyce Slaton
A Capoeira Primer
Better think fast on your feet when partaking in the Afro-Brazilian tradition of capoeira, the South American answer to martial arts. Set to a classic Brazilian pulse, the fluid hybrid of dancing and fighting (brawl-room dancing?) could leave beginners with bruised backsides. The ABADÁ-Capoeira San Francisco Brazilian Arts Center hosts a daylong Capoeira Competition and Song Festivalthat features matches for both kids and adults. Proceeds benefit the center's education programs. The fancy footwork begins at 6 p.m. at 3221 22nd St., S.F. Admission is $7-12; call 206-0650 or visit www.abada.org.
-- Nate Cavalieri
Be a Mess Mensch
There are so many beautiful things about San Francisco: stately Victorians, hilltop views, lithe yoga devotees sunbathing nude -- that is, if you're not too distracted by the mounds of garbage that litter our streets to notice. Sweepers suck up almost 28,000 tons of trash yearly, but as our rubbish-strewn roads and sidewalks prove, even daily sweeps can't fix the problem. Become part of the solution by volunteering with the San Francisco Clean City Coalition, which each month spruces up a different section of our town. This month it's taking on the area around the Bayview's Youngblood Coleman Playground -- and it could use your help. Show up at 9 a.m. at the corner of Hudson and Keith; all supplies are provided and a free lunch is served at the noon quitting time. Call 508-0050 or visit www.sfcleancity.com.
-- Joyce Slaton