Bike and mass transit, as we are one of the few places in the US that really has a comprehensive MassTrans system - about 170 miles North to South and about 50 East to West (complete with bike racks, so the bike goes with me everywhere). We all seem to bitch about GGT/BART/ MUNI/AC Transit/Caltrain nonstop, but the fact is that it's really a pretty solid system. Add to that bike trails that will get me 30 of the 60 miles between where I work and where I live (more that that, it's just that about 10 miles in the middle are missing, but they are being built alongside the new SMART trains) when I'm not working, and I really don't need - or want - a car.