Google is set to debut its most futuristic technology yet. Several Google employees say the company will begin selling augmented reality glasses by the end of the year. The glasses will have a small screen and a camera that will monitor the world in real time and overlay information about locations, nearby buildings, and friends who might be nearby. They’ll have a 3G or 4G data connection. The price tag is surprisingly cheap: $250 to $650. Google says the first glasses will be an experiment, and if consumers like them the company will then explore possible revenue streams.