I'm going to second the dog idea. Sure, someone determined to steal your stuff might bring a steak, but most crimes are opportunistic. If a dog starts barking before they even enter the place, why bother. In Atlanta I remember reading thieves were chopping through the sides of homes rather than using the windows in order to avoid the sensors and motion alarms. Good luck combating that. And a dog will probably bring some perspective into your life, make you care a little less about all that stuff.