While I want a smart fortwo or a different (but less cute) car, I think that at a certain point I don't need a car if I really don't want one, it just makes things rather impractical.
Where I live I can take the train up to the DC area, it takes a long time. I can also get around my local city with a bike, but some of the roads aren't really safe for it. A 50cc scooter is also good for that and gets about 100mpg, and feels a bit safe than a bicycle on busy roads. Even with $5 gas, it isn't too bad to get that sort of fuel economy.
A car is just simpler though, and the area I live in, public transportation is an after thought, not something that the local government seems to care about.