I did this last night, mostly as a joke. It’s a riff on CoughButton that just triggers some AppleScript to play a bell and make my PowerMate flash. It’s accessible from any web-enabled device on my network, so my wife can pick up her iPhone and summon me from anywhere in the house. It’s installable on the home screen, so I’m just two taps away at any given moment.
I’m not going to release the code for this as the setup gets technical and will be different for everybody, so it would be impossible to provide any support for (and likely impossible for anyone else to get working). It was fun, though, and I thought I’d share a video of it in action.