It's now been nearly three months since I owned a working car. My decision to go car-free was part forced by not having a running car and not having the means at the time to afford even another stopgap (a beater that costs little enough to be paid for with no financing), and part by choice.
Over the past few years, I had begun to notice just how expensive having a car can actually be. Aside from the sticker price, there's the cost of gas (not cheap), maintenance (also not cheap), insurance (not cheap; are you noticing a pattern?), the variety of fees required to keep your car street-legal (registration, inspection, etc.), and frequently here in Houston, tolls. The last one was actually an even worse issue when I lived in the far northern suburbs of Dallas and thanks to Rick Perry's addiction to toll roads, there was almost no feasible alternative.
All that money spent so that you can get yourself to and from work on a daily basis. You know, so that you can make money.
Of course, few people tell you about the alternatives to automobile ownership. Even in a city like Houston, which is essentially run by the oil industry (who of course wants everybody to drive everywhere), going car-free is possible. Or at least it's possible to go without owning a car. I ride the bus to get to and from work every morning. I walk to errands or I manage to work them in during my daily schedule. I do have a ZipCar account available for when I absolutely need to get somewhere that the buses won't go, like my frequent court appearances in other counties (where the local denizens don't want public transit because poor people, presumably.)
And you will not believe the reactions that this lifestyle gets within social circles.