shewolf51 said:
In the opening trailer for AC1, Altair jerks his pinky finger back, bending the finger wouldn't pull the string taught, thus not activating the hidden blade.
The opening trailer isn't canonical. It shows a Altair using a crossbow and shivving some dude he didn't even kill in the game.
OT:
I figured out a way!
This would require long sleeves and a small hole, but you could easily have a mechanism that extends to the backside of your hand. When you pull your wrists back (like revving a motorcycle) to get your fingers clear of the blade, it will depress the mechanism which will in turn trigger the folding mechanism which pops out the blade. The process could be repeated to return the blade to its holster below the gauntlet.
I obviously haven't drawn anything, as I am not a whiz at this or something, but I am pretty sure it could work, and you could still keep your fingers.