Al McWilliams, the 29-year-old founder of Quack Media in Ann Arbor, is one of 325,000 members of Zipcar, a company leading a car-sharing phenomenon across the United States, the Detroit Free Press reports today.

Nonprofits such as I-Go in Chicago, City CarShare in San Francisco and Philly CarShare in the Philadelphia area offer similar services. Demand for short-term wheels is growing so fast in these frugal times that rental-car heavyweights Hertz and Enterprise also are jumping into the business, the Free Press reports.

In Ann Arbor, that's led to a 78% increase in the car-sharing service in the last year.

• Read the Free Press story