Along with keys, keychains hold various miniature tools, gadgets, loyalty cards, and other random decorative things, but now you can have one of these cool new Mini Cactus Terrariums as well. Yep, tiny living cactus greenhouses that you can hang from your keychain or necklace now exist. The only requirement is that you water it once a month and, I guess, take it for a walk. Once this little succulent begins to outgrow the capsule, it can even be transplanted to a pot to live out the rest of its life. Available in a variety of cacti forms. Cool huh?