What about detecting the heat rise? Surely some sort of infrared camera system would show a temperature change. Of course it may take some work to convince people that you haven't hooked said camera up to the net and that you aren't charging odd people $30 a month to watch. Ok...maybe that was too far :) Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads