Losing your keys is the worst -- so it makes sense to do whatever you can to ensure your keys get back to you safely, should they be misplaced. For some that may mean attaching a Bluetooth-enabled location tracker, but I'd rather not have yet another bulky plastic doohickey on my keychain next to my flash drive. Luckily, the web has come up with a pretty low-tech method of ensuring your keys are returned safely. But first, you'll need to visit a pet store.