Most people think they're pretty cool if they bike across town -- and they are, but it's nothing compared to biking 4,200 miles across the country. That's what six teenagers are doing on their summer vacation, and the Coast to Coast BikingX Launch sends the kids (including local 14-year-old Aryeh Canter) off in style. Even cooler, the ride is a fund-raiser for Camp Quality, a summer camp for kids with cancer. Join the bikers on their first mile or just cheer them on starting at 9 a.m. at Justin Herman Plaza, Market & Steuart, S.F. Admission is free; call (800) 654-5957 or visit www.bikingx.com.
-- Hiya Swanhuyser
In elementary school, relay races were our teachers' sneaky way of getting us to learn about cooperation, teamwork, and how to be a good sport whether we won or lost. Now the Presidio Relay is reviving this childhood tradition with its 20K race. Gather friends for a four-person team, in which each member hoofs it for five kilometers before passing on the baton to the next victim -- sorry, runner. Not looking forward to getting up early on a Sunday morning? There's a bright side: The course is mostly flat, and the money goes to benefit Hands on Bay Area. The sprint begins at 8 a.m. at the Presidio's Glass Palace, Building 924, Crissy Field, Halleck & Mason, S.F. Registration is $30-40 per person or $120-160 per team; visit www.presidiorelay.com.
-- Jane Tunks