Assassin's Creed 2 Easter Eggs

To view this easter egg with your own copy of the game, you need to:
1, start the game
2, wait until it gets to the startup screen and says "press enter"
3, DO NOT PRESS ENTER!!! and do not move the cursor.... JUST DON'T TOUCH ANYTHING!!!!!!!!
4,... more

The first time you run into Ezio's uncle, Ezio doesn't recognize him so his uncle says "It's-a me, Mario!" This is an obvious reference to the famed Italian plumber from the Super Mario series.