Google is now using location-enabled mobile phones that have Maps for mobile installed to improve its real-time traffic data. According to the Google Blog:

Google won’t divulge exactly how many users of Google Maps for mobile there are, but it’s a central feature/app on the iPhone. It’s also available on the other major smartphone platforms. If roughly 50 percent of iPhone/iPod Touch users are in the US and there are 45 million owners of the devices around the world (according to Apple), it’s safe to say that there are many millions of location-aware handsets driving the morning and evening commutes.