MultiAlarm is a very nice system security app for the Mac. What it does is trigger an alarm when your Mac is used without authorization. The developer apparently decided to write this app because he would leave his Mac for a while and come back to see someone else using it. He did not like this. So MultiAlarm was born. There are two types of alarms that can be set up with MultiAlarm. The first one sounds an alarm when your Mac is moved. The app uses the Macbook's internal motion detector to know when it is moved. It can also deactivate the alarm automatically when the movement ceases. The other alarm goes off when your Mouse or Keyboard are used.
You set the alarms from the Preferences window. You can configure the sensitivity of the motion detection alarm and set both alarms to be activated after a time of inactivity, which is ideal if you forget to activate it manually.
There are two nice extras that come with this app. First, you can configure your iSight camera to take pictures and upload them to an FTP server when an alarm is set off. And it can prevent your Macbook to go to sleep when you close the lid if the app is active. This feature didn't work for me on 10.6.8, though.
