Enjoy the best things about the city on a Saturday afternoon: sustainability, music, and free admission. The San Francisco Bicycle Music Festival features an outdoor concert and bike parade, including a performance by Grammy-winning bluegrass outfit Laurie Lewis & the Right Hands — all fueled completely by bike power. Other headliners include Bill McKibben, founder of 350.org (via Skype, if you can believe it), and Jason Brock from last year's season of The X-Factor — remember that guy? In a massive sustainability effort to power the 15 bands performing, the festival features a 14,000-watt PA system powered only by bike pedals, a setup that's earned the title of the world's largest human-powered sound system. It should give a whole new meaning to "pedal to the metal." Just don't forget to BYOB, which you can imagine what that means.