Rainbow Six: Vegas Codes -

Cheat Mode
Start a game and press while playing, then hold and enter one of the following codes:

, , , , , , , , , , , - 3rd Person view
, , , , , , , , , - Big Head mode
, , , , , , , , , , , - One Hit Kills
, , , , , , , , , , , - Super Ragdoll

Text for Axe Easter Eggs
On the Fremont Street level there is a bottle of Axe on a ledge. Shoot the bottle and the roof on Fremont Street changes to an animation of a girl in a bikini with some Axe materials in neon. A movie opens up showing some outtakes and pretty funny Rainbow situations/early animations.

Unlock Weapons (In Campaign)
After destroying the opposition in single player campaign, don't forget to pick-up each new weapon you come across. While you don't have to keep a weapon and finish a map to unlock it in your customization menu, you do need to hold onto it briefly or your profile will not save it.

Another advantage is once you "claim" the weapon, you can die or restart the mission entirely and use it in the stage you got it from. This way, all the enemies you drop pretty much restock that weapon's ammo and you literally will be carrying a portable ammo dump throughout that stage.

Note: you need to reload your profile's last checkpoint each time you boot the game to get your gear back. If you choose to load a stage without loading your last checkpoint, your previously earned weapons will be lost.