According to FCC records, Bridgestone is close to releasing their wireless tire pressure monitoring system. The system uses sensors embedded just under the tire rim to send tire pressure and temperature to a handheld device. A 1.5 second alarm is sounded if the pressure is too high or too low.
I was bound by an NDA, but since the company that I signed that NDA with has gone out of business, I think I can get away with this now...
This tire pressure system may be the same one I worked on when I was at CrossLink. We had a tire pressure monitoring system we were making for Bridgestone. Ours was for giant mining trucks, and the readout was on a panel in the cab, but this looks very similiar otherwise.
Neat tech. Feels cool to say I built something useful once upon a time, as opposed to what I was doing at SignalSoft. :P