If you've got kids, you know that even taking your eyes off them for a second can result in them wandering off and getting lost. A reader at Daily Cup of Tech took a tool designed to help you find a lost USB drive and adapted it to help find his lost son.
The secret is to embed a simple "I'm Lost" program onto a USB flash drive, with information about your child, how to calm him down, and how to contact you. Put an "I'm Lost" sticker on the drive, and hang it around your child's neck. The tricky part is instructing your child to show the drive to his rescuer in the event that he gets lost. With any luck, your lost child will quickly be taken somewhere with a computer, they'll get your contact info, and you'll get a phone call.
Although it's a great idea, and I'm likely going to try it the next time I take my kids out somewhere they might get lost, I think it's got a simple flaw. It relies on the person who finds your child being smart enough to know what to do with a USB drive, and having ready access to a computer. You may be better off laminating a business card with the same information and hanging that around his neck instead.