During the Train Robbery mission, when your assigned to either knock or kill the station cheif, do which ever you please and then get the access code from the computer, which will open the door. After the door is open pick up the body of the cheif and then drop it right in front of the vault looking door in the hallway. The station cheif will stop in mid air and then start spazzing out, but will still be alive.
Also in the cruise ship mission you can do the same thing when the guard comes into the room at the start of the mission. Wait till he opens the door and then grab him from behind (or knock/kill doesnt matter). Then drop him more or less to the side of the door that leads to the small shower. He will spazz out and his legs will fly all over the place. (Note: if your trying to get trust for the station cheif opposing objective, you can knock him out if and then open the door which will give you trust to NSA, then if you want you can turn around and kill him, which will give you trust for JBA).
Ok for those of you that actually look this stuff up beware on the last level. For the first bomb that is to be defused, if you didnt kill hisham in kinshasa he will tell you how to defuse it the real easy way. If you did kill him this is how to defuse it, use your goggles to remote activate the count down sequence and sykes will defuse for fear of being blowing up. Kill sykes and jamie then procced to the second bomb. When you get there DO NOT REMOTE ACTIVATE THE BOMB UNLESS YOU WANT A CHALLENGE! ESPECIALLY IF YOUR IN ELITE MODE. Moss will let the count down sequence to continue and you have about 5 or so minutes (maybe less) to defuse the bomb with 4 to 5 guys in the room and a turrent to avoide/kill. After that go to the last bomb with emile and kill him by using a frag grenade from where you begin and hope your aim is true cause he is kinda hard to beat without your gun and avoiding the motion sensor bombs and his machine gun. (MAKE SURE YOU DO NOT THROW THE GRENADE TO CLOSE TO THE BOMB OR YOU WILL FAIL THE MISSION!!)
At the begining of the game (Iceland), get to the second checkpoint and turn the lever next to you, then go through the door and up the pole so the guy comes to the edge (kill or knock him out, really doesnt matter now does it?). After that turn on your heat vision then go a little further and look up, you should see a guy there. Shoot him in the head and continue, when you get to the part with the guy you shot he will be standing there but it will say he is dead (upper corner box says pick up body), weird isnt it? You can even walk through him but it wont do anything and he just keeps looking around, "Hey look a fly."
At the begining of the game (Iceland), get to the second checkpoint and turn the lever right next to you. After the door opens go through it and climp up the pole so the guy comes to the edge (kill or knock him out if you please). After that walk a little ahead and turn on your heat vision and look up, you should see a guy there. Shoot him in the head and continue, when you get up to the part with the guy he will be standing there but if you use heat vision he will be dead!! You can also go up to him and the little box in the upper corner will say pick up body, he will still be looking around if you look closely but he wont do anything, weird huh?