If you own a bike and are looking for a way to give back this holiday season, come out on Saturday to the Supermarket Street Sweep. In its fourth year, the event sends riders to designated grocery stores to purchase food items that will be donated to the San Francisco Food Bank. Participants can choose between a quick course or a cargo version, where the rider who brings in the most pounds of food wins. There will be plenty of prizes for participants from sponsors, including Bay Area specific messenger bags from Crumpler, handmade hats from Chuey, and a Soma Rush frameset. Last year's participants brought in over 5000lbs of food, all on bike! The event begins at the Bow & Arrow on Embarcadero this Saturday at noon.