Find lost keys, cell phones using a tracking device?

Hi there. I often find myself losing my keys, cell phones and other valuables. I am looking for a device such as the Loc8tor that can track all my valuables. Are there any alternatives to this device? Becuase that means you have to carry the tracking device with you everywhere. Perhaps by tracking by bluetooth and using a PDA? Is that possible?

I am sure there are tons of other people that run into similar problems.

Absolutely any help you can provide is appreciated.