Ping GPS Locator
Near-field trackers like Tile can certainly be useful, but if you need to keep tabs on something that moves around more than your wallet, you're going to need something more robust. Something like the Ping GPS Locator. It combines the more common Bluetooth tracking with GPS and a 3G cellular connection, allowing you to check on the location of something nearby or across the globe. Whether it's your luggage, your pet, or even your kid, it provides accurate tracking and up to three months of battery life per charge.