Simple IR Remote Control Testers

Digital, Web-cam, Video or Still Cameras - Infrared is visible to cameras. Allowing you to 'see' the infrared light emitted from the remote controls LED's. AM radio - De-tune the AM radio off station a bit. You will 'hear' the sound of the remote control through the radio. Optical Mouse - Use an optical mouse that dims when not in use. - Illuminate the mouse LED's by shining a remote into it. (Don't let other light shine in whilst doing this as this also lights the LED in the mouse) Oscilloscope - Use a glass signal diode (geranium - cats whisker style) to sense the infrared light emitted by the remote control. Do you know of any other SIMPLE remote control testers ?