I first tried to do something like this about 10 years ago. I wanted to put a microcontroller in every switch patress and network them across the mains using a TDA5051A modem. Unfortunately the size of the various components (including all the transformers and other passives) was too great for me to retrofit to exisitng hardware.<p>I've come back to this recently, as I can now use a ZigBee module for comms, and by going surface mount I can get the required components in a very compact space.<p>Never tried to do voice recognition in a socket, but that's a very interesting idea - have microphones in every patress and network them to create an array.