PCWorld: The U.S. has awarded Google a patent for "advertising based on environmental conditions." In other words, the search giant wants to tailor the ads you see based on conditions picked up by the sensors on your mobile device. If it's cold, they could sell you coats. If it's hot, they'll show you ads for cold drinks.
The patent also covers background noises. For example, if the device detects sounds from a sporting event or a concert, you could see ads related to those interests.
Google says that if it decides to deploy technology based on this patent, it will respect users' privacy.