Bluetooth is a short-range wireless technology that's been around for years. Most people associate it with loudmouths at Starbucks who use Bluetooth headsets to have personal conversations for all to hear.

But the new Bluetooth can do so much more than connect a clunky earpiece. Bluetooth 4.0 isn't just a little better than the version currently built into most mobile devices. It's massively better.

Bluetooth 4.0 has an extremely low-energy feature, which means supporting gadgets can run off wristwatch batteries, or hold charges for years, rather than weeks. For example, Bluetooth 4.0 enables wireless headsets that last weeks between charges. And it means that headsets can be a fraction of the size.

Wireless iPad keyboards don't have to be charged at all for the life of the iPad, thanks to Bluetooth 4.0.

Another magic trick Bluetooth 4.0 performs is that it allows pairing and data exchange without user involvement. If the user has granted permission in advance, two Bluetooth 4.0 devices can connect and sync data without even informing the user, just by being in range.