Meet the Sammy Screamer: a Bluetooth enabled motion alarm that lets you know when it is moved and sends a notification to your smartphone. Just stick it to things you want to keep track of, and the rest is easy. You can control your Sammy from your smartphone.
The device has a range of up to 30 meters. It is compatible with iOS and Android devices. The magnetized back lets you stick it on your stuff easily. Costs $45 at this time.