I'd prefer the bottle opener/keychain so I'd have a place to put my machine keys. I don't see myself ever wearing an actual pin-on button, though. I wouldn't need a full set of keychains, either. I'd really only need one. Do you have to produce in quantity to get good prices? I'd be interested in having 2 or 3 of the keychains, but that would probably be it for me. I'd probably want them in the largest size possible so I don't lose my keys (which I have a tendency to do since geniuses are messy).