Here is an interesting comparison of Cortana over the course of the 4 halo games:
PTesh adds his dulcet prepubescent tones over the top of one of the new trailers for weapons...
Try upgrading your browser to Google chrome (you wont regret it). There is probably an IE...
Halo 3 Boxart
In campaign, before you go in the room to review the Dawn's interior, look to your left and you should see a staircase that leads down. Look around and you will see a terminal. This also unlocks a 10G achievement. During the second part of listening to the terminal, zoom in on the terminal and look at the bottom left corner and you will see the Halo 3 boxart.