iPhone 4.0 was the first smartphone which introduces the Bluetooth into its Mac Mini and Macbook Air in this year.Its configured the data transmission, as macrRumors metions, some of the early possibilities to take advantage of Bluetooth 4.0 support things like health mointors, proximity detectors, and even "smart" watches. Once paired, they could send and receive data with your smartphone and display information quickly and without a huge power drain on either device.
The dongle syncs info with the app on your phone in the background, and so you don't have to even launch the app unless you lose track of your car. The automatic updating only causes a minor hit to your battery life because of the use of Bluetooth 4.0, although if you drive and therefore park a lot, you might find a bigger hit.
The industry has been slow in adopting Bluetooth 4.0 support, but this is bound to change as time goes on. This is the only the first of what's sure to be many devices that take advantage of the Bluetooth 4.0 standard. So far, the iPhone 4S is the only iOS device that supports it, but that will change as Apple updates its other devices.