A quick-draw iPhone holster is just what we all don't really need. Someone should definitely work that into a conversation with this Japanese guy who's been working hard to come up with a working prototype for said unneeded gadget. It looks like he's getting closer to achieving that, though, with the release of this video 'demo' where he shows off his prototype.
Dubbed as the 'iSleeve', this system will have the iPhone springing out of the holster and into your waiting fingers when you make a swift and sudden movement with your arm. It sounds neat and it looks neat, except for the one time that the phone flew out of the inventor's hand in the demo, but again, I doubt it'll ever get made commercially for the following reasons: it's extremely bulky, it'll render the arm that's got the iSleeve on virtually useless, and you might potentially ruin your phone in the process of getting it out of the holster.
But if you want to go all Assassin's Creed in real life with your phone (remember those spring-loaded blades up the sleeves?) then maybe you can ask this guy for some pointers on how to build your own.