I'm considering using my Mac Mini (mediacentre Mac) as a simple security system as well, with a motion detect enabled webcam. I've had an issue with break-in due to the block next door being a building site, so they can jump down to my terrasse and get in that way, without much trouble. But I don't see a reason for my Mac Mini to be on 24/7, also since sometimes I might be away for several days. I know that if you connect USB stuff to it, it will wake up from it's sleep. So, is there some how I can make a USB "trip wire" that will wake up the Mac, so that it will auto-run the motion detector software and start recording if something's going down? I don't know, maybe it's possible to take a USB cable and tinker with one of the ends, so that 2 of the connectors will short circuit and wake the Mac? Obviously this is not something I'll be doing with "trial and error" in case it does damage to the Mac's USB port as well I'me open to ideas and/or suggestions... Alternative I will just have to leave the Mac Mini running 24/7 Thanks!