LPT: test remote controls with your phone

I seem to use this tip about once a Christmas season. If you want to check if a remote control is working, look at it through your phone's camera. You cannot see the IR, but your phone can. If you see a whitish blue flashing light when you activate the remote, on the screen of your phone's camera then the problem isn't work the remote control.

This only works, obviously, work IR remotes, like TV's or, in this year's case, the controller to a Lego train.