There exists a reverse service where all information SENSED BY arduino or alike are SENT TO a server and you or anyone else can listen to the stream of data. It is called, let me think while typing, pachube. Most of these sensors are simple ones connected to arduino but the idea is pretty cool. I still don't know how to use a stream :(((
I think your idea has its merit. I agree with Rob too that you want to touch the wires. But having a server means you don't have to find logistics of connecting to a remote actuator or sensor array. The logistics right now has been ethershield and some wireless shield. You can use these to connect to google server or cloud to receive commands. Sounds like we are finally building skynet, after these many years.