ElectroTouch implements a novel way to detect household objects and locations within your apartment. It requires a special sensing cable, then it recognizes different locations and object touches after a single training example.
It characterizes electromagnetic fields, that you then send through OSC messages as objects are recognized to turn on lights, ovens or recognize different individuals.
Potential uses include personal authentication and home automation.
This is an instructable fully detailing how to make the cable, with some video examples: