CCD, the digital camera sensor, is sensitive to infrared light, such as the one emitted by all kinds of remote controls (if you don't consider prehistoric ultrasound models).
Webcams use CCD as well, so here's a screenshot taken with an old one to prove that it actually works.
The IR generator is a handheld device running the pre-installed IR remote control software.You can see the lighted IR-LED, a reflection on the left (double-bounce?) and another spot near the top border of the picture.
You can reproduce this experiment aiming a remote control to a digital camera lens. Then press a key while looking at the display.
Perhaps a simple way to explain some physics to kids?
