A good way to keep your current speed and momentum is to jump and switch weapons when you are in mid-air. Doing this comes in handy when you are being chased by someone in a Multiplayer game and you are low or have no ammunition for the weapon you are using.
Unlock Exclusive ContentAdded 3 Jul 2009, ID #1843
Select the 'Excusive Content' option at the 'Main' menu and enter the code 735S653J. If the code has been entered correctly you will get extra money for equipment in Single-Player. Extra money for characters in Multiplayer and weapons become silver in Multiplayer.