Markets In Everything: Hourly Car Rental Takes Off

FORTUNE -- For drivers who already share movies via Netflix and stream music rather than buying CDs, the idea of sharing a car is the natural extension of a hip, financially smart, and environmentally conscious urban lifestyle.

After all, drivers who give up their cars and switch to Zipcar say they save an average of $600 per month. Car sharers report reducing their vehicle miles traveled by 44%, according to Susan Shaheen of the University of California at Berkeley, and surveys in Europe show CO2 emissions are being cut by up to 50% per user.

You can now find Zipcars in most major U.S. cities, including Seattle, San Francisco, Atlanta, Chicago, and New York, and in college towns like Ann Arbor and Chapel Hill, as well as in Britain.

Perhaps the clearest indication of how big the car-sharing market could become is the entrance of rental giants such as Hertz (HTZ, Fortune 500), Enterprise, and U-Haul. Hertz launched a service in December in New York, London, and Paris that freely copies Zipcar, right down to the forest-green tones of its website and emphasis on a caring "community" of users.

Originally posted at Carpe Diem.