SF Bike Coalition is a non-profit organization dedicated to making San Francisco more bicycle friendly. They are a powerful political force in the city of San Francisco. There are over 10,000 members of the Bike Coalition, making it the largest politically-active membership organization in the city and the largest bicycle advocacy organization in the country.
SFBC members get a 10% discount at most Bike Shops in the city as well as some other businesses such as Arizmendi Bakery.
The SFBC is a volunteer-run coalition. Any member can take part in several volunteering opportunities on a regular basis. Every second and fourth Wednesday of the month, volunteers gather at the SFBC headquarters and indulge in free food while either folding the Tube Times or doing one of other many other duties needed to stay functioning. SFBC also provides a free bike valeting service for most of the City's major events, and volunteers to valet are always needed. See their volunteer page at http://www.sfbike.org/?volunteer for more chances to help out.
Learn more on their website: http://www.sfbike.org