I was trying to diagnose a problem with my Hauppauge WinTV remote on my MythTV box, and I wanted to tell if it was the remote or the card. So the Hauppauge tech support told me to hold the remote control in front of a digital camera and see if I can tell if the IR signal is being sent out from the remote.
Apparently digital cameras can capture infrared light, something I didn’t know and thought was cool.

Since then, I found this helpful site on many techniques to troubleshooting handheld remotes.