I actually found this on someone else's blog :p
dunno how i missed it! but its awesome nonetheless!! check it out..
head over to the Assassin's Creed teaser site .. after the video etc.. plays through(wait patiently)
wait till you get to this symbol
click on it and it opens a 5page pdf.. print that or trace the 5 symbols off of the screen(:spock: works, have done it before)..
next click on this tab
now click on the first tab on the side
and hold up the first symbol infront of the camera
it analyses the symbol and unlocks the hidden content
and taadaa!!:yes: you see a 3d model of the assassin's famous hidden blade!
the other tabs give you other stuff..:cheers:
heres some of it
heres a video of how it works..
for more details on the Assassin's Creed game and other goodies, check out this blog this guy has been painstakingly documenting the whole thing. he also has videos of all the stuff ive talked about above.