Meet some commuters who are doing just that and saving money.

"You don't need a car 24-hours a day," says Seattle freelance writer Ron Holden. "And if you can be assured of having a car when you need it, why not share cars?"

Holden is a member of Flexcar, a Seattle company that allows drivers to share vehicles for a fee.

Perhaps you've seen cars with the Flexcar logo parked in marked spaces around town. The company places cars in convenient locations for use by its members.

"The American Dream really is...you say it's the dream of car ownership," says Flexcar president and CEO Lance Ayrault, "it's really the dream of convenience."

Flexcar vehicles are placed in public places like the train station and public library, as well as in neighborhoods and even private driveways.

Basic membership costs $35 a year, and drivers pay an additional $9 an hour to use the cars, which includes gas, insurance and maintenance.

The most common way members reserve a vehicle is online. Each member then uses an electronic keycard to access the cars.

Holden is convinced he's saving money doing it this way.

"I had one month where my bill actually reached $150. The rest of the time it's been under $100 and several times under $50," he says.

Some employers will even pay for employees to join Flexcar knowing it's another way to reduce traffic congestion.

Proponents of car sharing programs estimate one shared vehicle takes the place of six individually-owned ones.

Flexcar is not alone. Another company called Zipcar is based in Boston and offers fun cars like BMW Mini Coopers to its 32,000 members in Boston, New York and Washington, D.C.

Between Zipcar and Flexcar, car sharing programs are available in about three-dozen U.S. cities.