For those of you without cars, biking may be one of your best options for getting around the local area, since there are bike paths which will help you avoid the worst of the traffic. In any case, since Stanford is a huge campus, buying a bike may be one of your first purchases even if you do have a car.
We don't recommend one bike shop above the others, but the closest ones are:
The Campus Bike Shop: Tressider Union, 459 Lagunita Drive #12
Cardinal Bike Shop: 1955 El Camino, near the intersection of El Camino and Stanford
The Bike Connection: 2086 El Camino, near the intersection of El Camino and Stanford
You can also check out supost.com where people often list bikes. If you want to do a more extensive bike search or have particular tastes, check out the Yellow Pages.