A while ago we posted about OrangeSec adding commands to Cortana using a man in the middle attack.
At the time everything died down, but it turns out the team had in fact published their code to enable anyone to take advantage of their work. Their CortanaProxy can found on GitHub, and when running on a server (such as your PC or even a RasberryPi) allows users to intercept voice commands via Cortana and program in responses.
A bit more hacking allows users to do something useful such as using another service like LightwaveRF to activate your lights, which is exactly what Andrew Kerr did in the above video.
While such hacks are by their nature likely to be shortlived, until Microsoft close the loopholes, we wish until then some-one could package it into an easy to use feature that will let the rest of us into the fun.
Thanks Andrew for the tip.