It's been about a year since I sold my car and started an ongoing experiment to see if I could live, work, and play without owning an automobile in one of the most car-dependent large cities in the US.
Last spring I joined a car-sharing service called zipcar in anticipation of selling my car. I did all the math and realized that using zipcar would be much more cost effective for me in the long run. I barely ever used my car, and when I did, it was for pretty short trips to the grocery store or other nearby places.
Summer of 09 was when I sold my car to a good friend and former Alice in Chains coverband-member from home, Craig. I still had plenty of options for getting around in Atlanta: MARTA trains, buses, my bicycle, bumming rides off my roommates (thanks boys), and zipcar. In the year that has gone by, I have only taken a legitimate MARTA bus (not including the Braves shuttle) once, but I use the trains all the time to get to and from the airport.
Up until September, I rode my bike pretty much everywhere and got fairly knowledgeable about which roads were good for biking, where the bad potholes are, and where drivers were the most courteous and willing to give room to bikers. Peachtree Street, which is basically the main street of Atlanta, has always been one of my favorite roads to ride on because traffic moves pretty slow, there's lots to look at, and drivers usually give you plenty of room. Edgewood is another excellent road for biking, and it connects many of the East Atlanta neighborhoods to downtown.
Then I decided to purchase my 50cc scooter almost on a whim. After going through the HOT summer months mostly on bicycle, I realized that it would be pretty convenient to have some kind of motorized vehicle to get me around without being constantly drenched in sweat. My dreams of zipping around the city on a little scooter became a reality, and I stumbled across a transportation revelation.

My scooter outside our new house in Atlanta.
Scooting is the greatest way POSSIBLE to get around the city of Atlanta!!!
You don't need a license. Or registration. Or insurance. You can park it ANYWHERE without ever having to pay for a spot or going through the oh-so-awkward valet parking exchange. I regularly get about 70 miles per gallon, and sometimes it'll even get 90mpg. It is by far the cheapest and most convenient way of getting around. Also, it has a super convenient basket in the back, which makes it perfect for scootin' on over to the grocery store for some supplies.
There are only a couple small problems. Atlanta is a fairly hilly place, though it's downright flat in comparison to
The Paris of Appalachia (my new favorite nickname for Pittsburgh). The scooter tops out at about 40mph on a flat surface. When i'm going up a steep hill, I'm lucky to hit 25. Those car drivers don't appreciate that very much when they're hurrying to get to who-knows-where. Also, it's not the most fun thing to ride in the rain. But neither is a bicycle or motorcycle.
I still love my bicycle and ride it to and from work pretty often. I still use zipcar when I need to pick up some furniture or what not, and I still ride in my roommates' cars when we all want to go out to a bar or the farmers market. But from now on I will always be an advocate for the scooter. After one year, the car-free experiment has been a huge success, thanks to the awesomeness of the scooter, the ingeniousness of the zipcar car-sharing program, the amazing durability of my second-hand mountain bike, and the goodwill of my roommates and friends.