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...
Level: Sierra 117
When you get to the part where there is a brute holding a marine by his neck and asks "tell me its location" he will say "kiss my ass" after killing all the enemies go to the bridge where the marine was, near that bridge (off towards the path you came from) is a tree, jump in between the trees branches and if you look around you should find a carving that says "m+l (and a date)" surrounded in carved heart.