These codes for Splinter Cell are from gamefaqs.com, but I reformatted (Or tried as much as possible) them to be easier to read... however if you've got an easier way to format them be my guest... as per usual, if you notice any errors or anything that just don't work... feel free to fix the page.

NOTICE: On the 360, Black Button = Right Bumper and White Button = Left Bumper.

All Levels

Type !lamaudite! in the name entry screen. Thats ! l a m a u d i t e ! all together. Contributed By: theimpossiblenick

Walk around in second Chinese Embassy level

This glitch lets you walk around in an area you're not supposed to. This glitch requires near-perfect health, so don't get shot at. Make your way through the restaurant, up the ladder, and across the makeshift wooden bridge. Take out the guy with the flashlight helmet, and proceed. Make your way to the zipline, but don't zip down it. While on the balcony looking out, turn to your left. Jump on top of the box, then on top of the balcony railing. You should slide forward, turn around, and catch the railing automatically. Now shimmy over to roughly the middle of the railing, then hit down on the control stick to drop. Immediatly press and hold B. You should land with a small amount of health left. Explore this glitchy area, but don't wonder too close to the building you were supposed to zip to or it's misson failure. Contributed By: TaOpOcL

Non-Lethal Bullet

If you find yourself running low on non-lethal bullets in your SC-20K, use the sticky camera at close-range to knock opponents unconcious. It's on par with the ring airfoil round. The sticky camera can be picked up and used again.
Contributed By: Halo2Hopeful

Secret Room

On the first level (training) there is a secret room above where you start. At the start look to your left. There is a ledge. You've got to get up there. Wall jump up there and goto the keypad and press: 5656. Walk in there into the secret room!! The way to figure that out is there is another ledge oppisite it. WAll jump up there and open the door into a storage room. Pick up the lock picks, go through the course untill you get to the gate you need to wall jump over. There is a locked door there, pick it and use the computer. It should give you a data stick and a note. Go back through the course and do the above! Contributed By: coola

Skip a Hard Battle in KolaCell (Server Room)

Note: KolaCell is available through downloadable content or a demo disc. In the server room, after you access the computer and get the checkpoint, open your items menu with the black button after the Colonel starts talking. Keep it open until he is finished, then close the menu. Normally, 3 guards are supposed to come storming in, but if you do this trick they will not arrive! Also, in the hallway with the camera, the wallmine will not be there, so you don't have to stop and disarm it. Contributed By: DaruniaTheGoron