I'm a big fan of audible alarms, monitored or not, if your 180 decibel alarm is going off, most perps realize they have 30 seconds or less to get out of Dodge before they begin to get detected getting out of Dodge. Connected to door sensors and window sensors, even glass break sensors (pricey), you don't always have to wire your entire house for protection, but unless you're handy with wiring I recommend contacting a security firm for a reasonable strategy and installation.

For an element of prevention, a friend swears by cameras that are motion sensitive and can trigger his cell phone or work PC. Something like this I think - http://www.bestbuy.com/site/Logitech+Alert%26%23153%3B+-+750e+Outdoor+Master+System/1230961.p;jsessionid=198D9E0BA79970775D81BE89FEE3B264.bbolsp-app04-26?id=1218239220969&skuId=1230961&st=logitech outdoor camera&cp=1&lp=6 . Problem being of course, a burglar will go to the first unmonitored point of access and try that.

Dogs are good too, but mostly as a deterrent - they'll alert you if you are home, but are not generally a serious obstacle to an intruder if you're not. Unless they are trained to attack unattended strangers in your home, which I'm not sure many are any more for obvious reasons. Dogs will bark, they might even put up a fight - you can lock them in a bedroom and continue sacking the place. Dogs do enter into the calculus whether to enter a home - unless you have something they know they want (like guns, cash, prescription meds etc), most burglars will hold out for the safest place to burgle. A barking dog should make most try another house down the street (without a barking dog). But like Dagny says, its a 15 year investment, don't buy a dog just as an anti-theft dongle.