So, I'm thinking along the lines of building automation. They do this with lighting on really high end systems where I assume they have a PC running. The arduino system would be plugged in to an outlet, etc., and would get the equivalent of a button press from a phone call or something along those lines. Feedback wouldn't really be necessary, just someone calling the thing to tell it to start. Ideally, there's be an iphone app to activate the arduino system remotely... that sort of thing is what I'm dreaming of. Under $100 would be good too 
Thanks