Fed up of being interrupted while on global video conferences I hacked together an on-air lamp to as a do-not-disturb icon. Something like this
I could have simply placed a red light bulb above my desk and hit the switch every time I joined a Google Plus Hangout but obviously I wanted something automated. After a bit of digging through the the Google Plus API for Hangouts it seemed relatively straightforward to write some code to detect when a hangout is entered/excited. With that in mind the next step was to figure out how to get that information to the physical world.
Well some months prior I had ordered an el-cheapo handful of parts from the UK to build a blinkystick.