Just whistle to change channels

RFID in Japan reports on an electronic tag (the yellow piece) which can be attached to your tv remote control. The black piece is a whistle. When you use the whistle, the tag hears the sound and responds to it by making a another sound, lighting a LED, and changing the channel (I hope I got that straight).

This system may be good for some purposes -- before RFID-based solutions are widespread.