Bluetooth is wireless technology for PC's, handhelds and other devices. Quote: "Bluetooth wireless technology is a short-range communications technology intended to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. The key features of Bluetooth technology are robustness, low power, and low cost. The Bluetooth specification defines a uniform structure for a wide range of devices to connect and communicate with each other. Bluetooth technology has achieved global acceptance such that any Bluetooth enabled device, almost everywhere in the world, can connect to other Bluetooth enabled devices in proximity. Bluetooth enabled electronic devices connect and communicate wirelessly through short-range, ad hoc networks known as piconets. Each device can simultaneously communicate with up to seven other devices within a single piconet. Each device can also belong to several piconets simultaneously. Piconets are established dynamically and automatically as Bluetooth enabled devices enter and leave radio proximity. A fundamental Bluetooth wireless technology strength is the ability to simultaneously handle both data and voice transmissions. This enables users to enjoy variety of innovative solutions such as a hands-free headset for voice calls, printing and fax capabilities, and synchronizing PDA, laptop, and mobile phone applications to name a few." # http://www.bluetooth.com/Bluetooth/Learn/Basics/ # http://en.wikipedia.org/wiki/Bluetooth It's popular because it works, and it works well.

Bluetooth is a standard/specification for wireless communications on personal devices. It basically creates what is known as a Personal Area Network (PAN). It is popular because it enables us to get rid of our wires. (Such as a wireless Bluetooth headset for your mobile phone. No wire connects the headset to the phone.)