Alarm systems are fantastic to protect your home while you're not in it, by sensing motion within the house. Also, signs that you have an alarm are great deterrents!
You can also get varieties that turn on in specific rooms (so can be activated after you go to bed) and also come with panic buttons hooked up to a security company or the police. Alarm systems can alert people around by sounding a siren or alarm, or they cansend an alarm to a security company who will send a response unit out if the alarm goes off.
Most alarm systems are sensor based but some can be fitted to doors and windows and sense breaking windows or opened doors. Either way, your sensors must be consistently placed throughout your house.
Putting up a sign that you have an alarm is also a great deterrent, and something to think about even if you don't have an alarm. Of course, dogs can be useful to alert you to intruders while you're home but let's face it, that relies on neighbours being home or the dog being properly fierce!
Victorians: To see how your neighbourhood's crime statistics compare to others, go to the Victorian Police'sMy Place website.