Keeping track of your keys can be a daunting task. This is an idea that will help those poor souls who frequently find themselves locked out of their cars, offices, homes, etc. This concept may also be applied to any item that is usually in close proximity to your person.
Usually when you realize
that you have lost your keys, you may well be quite some distance away from where they are located. In this scenario your first thought after searching your pockets is, "where did I leave my keys?" Obviously a beeping key chain is not going to help if the keys in question are out of hearing range. Ideally you would look at a map and see where your keys are located.
Two existing technologies may make it possible to keep track of your lost keys:
The first is GPS, or Global Position System. These devices are widely available as handheld devices. It is not inconceivable that they could be manufactured in the form of a wrist watch.
The second is RFID, or Radio Frequency Identification. These small chips will soon replace the barcode as a means of identifying products in warehouses and retail locations. They do not require any power of their own, but operate on the power of the scanning signal. As such, these devices are practical only within close proximities.
By combining these two technologies, you could have an economical solution for the chronic key-losing individual. A wrist watch would monitor the location of your keychain (that is embedded with an RFID), and would be able to display the last know postion via GPS information.