Bay seniors who think the SF Civic Center Plaza is just a gathering spot for bureaucrats and sunbathing homeless are in for a big surprise this coming Friday, Saturday and Sunday when it becomes the site of the Dew (as in Mountain Dew) Tour. Temporary hillocks with become tracks for a major BMX (Bicycle Moto Cross) and Skateboard competition, as riders try and outdo each other flipping, flying and performing tricks from early in the morning until midnight. Geezers with their own bikes and skateboards (are their any out there?) are invited to try the courses. Live music. Free.