Google Ventures has invested an undisclosed sum into RelayRides, a car-sharing service similar to Zipcar, to help it launch in San Francisco Tuesday. August Capital also took part in the company's first round of fundraising, according to VentureBeat.com.

RelayRides allows car owners to list their vehicles on its website and make them available for car sharing. The owner sets the price and what time of week the car will be available for rental. The owner then gets 65 percent of the total rental fee, and RelayRides takes a 15 percent cut. The other 20 percent goes toward an insurance policy.

RelayRides inspects all vehicles before they enter the system. Once a vehicle is listed on the website, RelayRides will install a small computer in the owner's car to control the door locks and ignition. Borrowers wave their member cards over a reader on the car to unlock the doors. The key is in the car. Cars are also equipped with GPS devices to locate vehicles and track miles.

Borrowers can reserve cars online or via an automated telephone line. Borrowers' driving records are checked by RelayRides. Borrowers who return a car late or dirty multiple times are removed from the system.

Owners are responsible for maintaining, cleaning and taking care of the car. They are docked a small penalty if their cars are not available at the time of the reservation. As in other peer-to-peer programs, owners and borrowers are held accountable by a review system.

RelayRides was founded in November 2008 and launched its pilot program in Cambridge, Mass., in late spring 2010.