Owning a car is really expensive—and Seattle's public transit system sucks. So today in Seattle, a new company is launching an app called Sidecar that would help connect drivers with folks who want to carpool. Initially, it will only be available from 6:00 p.m. to 2:00 a.m. on Friday and Saturday nights.

It works like this: People who need rides will open the app and drop a pin where they need to be picked up and the address where they need to go. Nearby drivers will get a notification and, if they are available, go pick up the wayward traveler. The app suggests a donation amount for the ride and Sidecar charges the credit card the users have on file. At the end of the ride, there is an opportunity for both rider and driver to rate each other and the enjoyability of the ride. It's a bit like the couchsurfing.org model, which uses peer reviews to verify the credibility of the users.

The San Francisco-based company is expanding to Seattle because of the demographic and cultural similarities between the two cities. they say. "Seattle’s tech savvy populace and culture of innovation make this city the logical next choice to accelerate the crowdsourced transportation movement," said CEO Sunil Paul.

I've used Craigslist to rideshare, but Sidecar seems less sketchy, given that there is a record of whose car you're in, when they picked you up, and ratings of the driver from other users. San Francisco is a pioneer of ridesharing within the US but socialists Europeans have been doing this forever. Ridesharing in Berlin—or Mitfahrgelegenheit—is popular and effective. Who knows if it will catch on in Seattle, but for folks paying tolls to cross 520, people who don't want to take the bus, or drivers who want to cut their gas bill, hey, this may be just what they need.