This cool little knife by Everyman was specifically designed to blend in with your current key setup.
It's made of hardened 3CR13 stainless steel and includes a discrete, duel-layer bottle opener that's more "James Bond" than "Coors Light enthusiast." It's also (and this is important) incredibly lightweight, so you barely notice the addition to your keyring and pocket.
At just $21, there are few EDC additions that will make such a big impact for so little money. Get one in your life today.