San Francisco proper and the middle of the Valley (Palo Alto, Menlo Park, etc.) are very different -- from San Mateo down to San Jose you pretty much need a car

San Francisco proper and the middle of the Valley (Palo Alto, Menlo Park, etc.) are very different -- from San Mateo down to San Jose you pretty much need a car since everything is very flat and spread out compared to, say, Manhattan or Boston.