I am uber psyched aboot Assassin's Creed.
Got it Friday. Haven't really been able to play it much....but it's still awesome.
Altaïr's signiture weapon in AC is the hidden blade, which is a retractable knife hidden on his left arm that can be used for killing targets at very close quarters without creating any immediately alerts.
"Altaïr's most interesting weapon is a mechanical dagger that it used for close-range assassinations. It is mounted on the inside of his left hand gauntlet, and when deployed, extends between his middle and pinkie fingers through the space left by his amputated ring finger. This amputation was part of the initiation for becoming as assassin of the Hashshashin sect."
-Wiki
Well my friends, I wanna make it.
I was thinking of using springs and some mech to lock it in its retracted position until the mech is unlocked by pulling a string attached to one of my fingers, thus springing the knife forward into its extended position.