Cool! I've seen something like this on a newer car. I work as a car prep for a car rental company and our 06 Mazda 636's have these keys that flip out like switchblades.
The remotes are black and about an inch and a half long with all the remote functions (panic, lock, unlock) on top and a small silver button at the top. Press the button and the key flicks out of the side. Very nice! Hadn't seen anything else like it until now. i so have to make one of those.