You know you've always wanted one, and now they're real: the Star Trek communicator badge is available for purchase. Simply say the name of the person you want to speak with and the built-in voice recognition system figures it out and patches you through.

Of course with every mammal in the developed world already carrying a cell phone, this doesn't really add a new communication channel. By making the connections quick and transparent, though, it seems that this becomes something qualitatively different from a phone call. Will we all be linked this way in a few years?

See the videos and documentation.