Well, especially if you live in an urban area, why not look into car-sharing?
When you join a car sharing program, you can have access to cars for as short or as long a time as you need them. You can take one for an hour to run an errand or pick someone up at the airport-- or for days at a time. They have a variety of different cars, and numerous convenient locations. Over 100,000 people are using these programs nationwide, and many more around the world.
There are a ton of benefits, financial and environmental, to car-sharing. Obviously owning a car is really expensive, between purchase price (and interest if you have a car loan), insurance, parking, maintenance, fees-- so skipping those costs can be hugely beneficial, depending on how often you'd use the shared car. I've seen it cited many times that car sharing is better financially than owning if you drive less than 7,500 miles a year (I can't vouch for the figure, since I haven't seen the original source/how it was calculated). This also works well, by the way, if you need more than one car but you don't really need two.
But the real beauty of car sharing is the way it forces you to think about whether you really need to use a car or not. If you have a car in the garage, it's very so easy it to take it wherever you're going, even if it's just down the street. That's bad for the environment, and it's not so good for your wallet, either. On the other hand, if you have to pay for your shared-car usage as you go, it's a great way to get yourself considering if there are other, better ways to travel. More walking and biking is good for the planet, your health, and your happiness, and it's blissfully free. And public transit, too, is environmentally friendly and cheap. Yet those shared cars are still available if the car really is the best way to go. In a lot of ways, it's the best of both worlds.
Another environmental benefit: many of these programs make a point of filling their fleets with hybrids and other high-fuel-efficiency vehicles. Of course, this varies from program to program; Your Mileage May Vary. (Sorry, had to say it!)
Check out this MSN article, which talks about a lot of the benefits of shared cars, and be sure to scroll down to the table at the bottom, listing 41 cities with shared car programs complete with links-- some locations may surprise you! (Also, here's another perk-- the opportunity to drive a wide variety of new, different cars.)
The MSN article gives you links to just about every car sharing program there is. And other resources include articles here, here, here, and more-- just search around!