According to the laws of the universe written at the time of the Big Bang, things are supposed to go AWOL for absolutely no reason while we desperately try to find them. Keys, tv remote and pens are the worst offenders that love to go invisible at just the time they would be needed.
The concept is basically a two part system with a main terminal and stickers with embedded RFID locators. The stickers can be configured as labels, and when you need to find something, all that needs to be done is to start off the main terminal, and it will automatically look for the object required.