RFID technology has not made as much of an inroads into consumer use as originally predicted by some experts. At least not in the expected time frame, with widespread adoption expected to take much longer. In fact, a lot of announced future applications are still prototypes. However, there already are RFID applications in use that are little known.

For example, 150 million car keys have had RFID technology since 1991. Such a key has to match up with a sensor in the steering column, or the car won't start. So counterfeit keys will not work. [via WFAA.com] Well I'll be! That's one app I wasn't aware of. And 15 years in use, too.