You might remember the Split Ring Key, a clever twist on the keyring by designer Scott Amron that let you hang your keys on another key. The split-ring design, however, made it a chore to add and remove keys. Solution? Put a hinge on that sucker and ta-da: the CarabinerKey.
Seems like a handy addition to your keychain — might even simplify things a bit. The site says you can order them, but I’m guessing they’re not quite to the level of retail availability. Price isn’t set, but the old keys were $8, so I’d guess these would be a bit more due to the multi-part manufacturing. $10 maybe?