Sprinkler Hide-a-Key from: thinkgeek.comHide your keys by pushing them into the ground!How clever! Instead of leaving the key under the mat, here is a safer way to leave your key for your guests while you’re out. You can order them for only $5.99 each! “Rather than the old standard under-the-doormat or inside a plastic rock, this fake in ground sprinkler head offers a good place to put a set of spare keys