I work for Texas Instruments, a company that makes chips for cellphones, wireless technologies, digital cameras and TVs. We have lots of creative people here, (and to be honest, I don’t come in contact with most of them!).
Here’s my brilliant idea. Have you ever called someone only to find out they are in their car or at work or generally in a situation where they shouldn’t be interrupted?
Cellphone carriers should be able to indicate a user’s status (like you do for Instant Messaging). The problem is that users don’t want to constantly be changing their status (they’ll forget, or they’ll forget to turn it back).
Often, their status is a result of location. For example, if you are at work, that is a specific geographic point. Same for In Car, etc. It should be a relatively trivial matter to invent a “proximity beacon” which you can put in your car or workplace to automatically register when you/your phone enters that space. Once the phone comes within range of such a beacon, a status change would be registered with the carrier. The carrier would let you keep a buddy list or at least assign a certain status to entries in the address book.
Imagine if a movie theatre or church could have their own beacons to indicate status (Movie/Church/Shopping). Yes, there are privacy issues to deal with. But individuals could elect to turn on this feature and broadcast it to the network. The question becomes: would individuals mind sharing their status (expressed in vague generalities).
Consider Instant Messenger. I am not a big fan, but I appreciate how you could change your status to make yourself unavailable or even invisible. For a while, I just left things on default, but as my buddy list grow, I was “invisible” more often than not. I didn’t want to be bothered. Some people on my buddy list were acquaintances I’ve lost touch with. Others were people who just liked gabbing. After the novelty of instant communication wears off, it becomes really really annoying.
The problem with turning your cellphone on vibrate or silent is that it requires user action. And users sometimes forget (or worse, they forget to turn it back to its previous setting). For a permanent solution it is unworkable and cumbersome (though by now we’ve adapted).
You could manufacture “location beacons” for next to nothing, although the big hurdle is in adding it to the carrier’s bundled services. Given the diminishing number of cellphone options, there may no longer be a need to differentiate your cellphone service. If Wifi or mesh networks were robust enough to maintain a signal, the idea could be implemented just as easily.