One of the less ballyhooed features of the iPhone 4S is Bluetooth 4.0, something only found on a few devices so far. This new low-powered version of Bluetooth can open the door to lots of interesting uses for the iPhone 4S, including all kinds of health industry uses as mentioned by CNET. Closer to home, I can envision Bluetooth 4.0 and the iPhone 4S doing fantastic things with my watch.
The MetaWatch I am wearing is already Bluetooth-enabled, albeit an earlier version of the standard. It uses Bluetooth to connect to my Android-powered Nexus S 4G to keep me informed about the things around me that matter (email, weather, SMS messages, and incoming phone calls).
This "personal grid" is very useful to me on a daily basis, but that could take a big jump with Bluetooth 4.0. It's great that I can leave my phone in the pocket and see who is calling me by glancing at my watch. Bluetooth 4.0 would allow that to be taken to the next logical step of using my watch has a hands-free device to take the call. The phone stays out of sight but I can still use the phone at will.
The Siri technology on the iPhone 4S could take that utility even further if the watch had Bluetooth 4.0. It would be fantastic if I could tap a button on the watch and talk to Siri. I could ask questions and hear the answers right on the watch, using the iPhone 4S as the little engine that could.
This is not something from the distant future, this could be done today with the proper investment in Bluetooth 4.0. The MetaWatch already has become a major piece of my mobile toolkit but the sky's the limit with the doors the iPhone 4S open up. Are you listening, MetaWatch people?