General Motors has partnered with RelayRides (a "nationwide peer-to-peer car-sharing network") and will use its OnStar technology to help owners more easily rent out their personal cars as a way to make extra cash and keep excess cars off the road. RelayRides launched in Boston back in 2010 and has since expanded nationwide; vehicle owners who participate offer up their own personal car for short-term rental through an online portal, similar to the Zipcar service.

What GM and OnStar will bring to the table is a much more streamlined way for renters to gain access to vehicles — RelayRides vehicles with OnStar will be able to be unlocked with a smartphone or by replying to a text message, eliminating the need for a face-to-face meetup to swap keys. While OnStar didn't say whether they were launching dedicated smartphone apps, images in their press release made it seem this functionality was accessible through a mobile browser. OnStar also makes it easier for car owners to register their vehicles with RelayRides — users can just log in to the OnStar site and share a vehicle with a few clicks.

While some probably find the idea of renting out a stranger's car to be a tad unconventional, a service like this that makes it easier for both car sharers and renters could help it gain more adoption. If RelayRides wants to compete with services like Zipcar, having an automated way for renters to pick up a car is some pretty crucial technology — of course, this automation is currently limited to GM cars with an OnStar subscr ption.