If you are a touring performer, at some point or another, you are going to lose gear. Whether you absent-mindedly leave your audio interface in a venue or, as happened to me many years ago, your band's entire U-Haul trailer gets swiped, if you play any amount of live shows, you're probably going to have some gear go missing.
The Insignia Little Buddy is a device designed to put somewhere on the person of your child to keep track of them, especially, one presumes, if they were kidnapped. I think this is an idea waiting to be adapted for musicians, however. The current model is a bit bulky for this purpose, but imagine if it came in an ultra-thin "sticker" form. You could open up each piece of gear, attach the sticker/GPS transmitter to the inner lid of said gear, and in the event that it got stolen or forgotten in a hotel room somewhere, you could look up its location instantly.
I've heard rumors of similar products for musicians, but nothing that really seemed ready for prime time yet. I'm telling you, though, the company that puts this in sticker form and offers a cheap monitoring charge is going to make a lot of money.