But another company, MicroTrax in Montana, does that and adds an extra level of security with MicroDots. These tiny ID tags are the size of a pin point. They are glued to devices using an adhesive that can be seen under ultraviolet light. So, if a thief rips off the larger, visible label, the discreet MicroDots still offer evidence of ownership since each is encoded with microscopic ID numbers. MicroTrax, which has more than 10,000 items registered in its database, works with law enforcement to help identify and recover stolen goods. Owner Bridger Stratford has one main tip for users: Don't forget to register items at Micro-Trax.com so the service can do its job. A surprising number of buyers don't bother with that simple step, he said. The $50 kit includes a year of service, which is $30 annually. Zomm Another mobile app mashed with key fob, Zomm has been around a bit longer than the rest -- two years. It uses Bluetooth to link a smartphone (Android or iPhone) with the key fob. But beyond finding keys within 30 feet of the phone, Zomm adds a few other features, including turning into a speaker for hands-free talking while driving and acts as a panic alarm. The Zomm is $60, while the apps are free at zomm.com.