Yesterday we asked : what other unexpected motion-based apps will people come up with that just aren’t on the map today?

Today’s news brought a great example: software that determines when a mobile phone is being used in a car and which diverts incoming calls to voicemail and “holds” incoming text messages until the phone (and the car, presumably) is no longer moving.

We should disclaim that this is an app based on GPS built into phones and not on accelerometers, but it’s still a great example of a unique way of leveraging motion (in a macro rather than micro sense in this case) to build intelligence and presence into applications.

The company behind it , Aegis Mobility, is positioning the product as a safety enhancer (there’s even tie-ins with insurance companies) and as a personal assistant that “knows” what you’re doing (driving a car) and routes your communications accordingly.

We think that a lot more can be made of such applications — using a combination of motion sensing and GPS-based location awareness and even the camera built into phones to provide intelligent apps with some situational awareness — knowing where you are, what you’re doing (or what your movements indicate you’re doing) and even what you can see (through the camera’s lens) to provide greatly enhanced navigation, location-based services and presence-dependent services.