These codes for Amped are from gamesradar.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.

First go to the options menu. Next pick Cheats. Once there Type in RidinwRaven. If cheat entered correctly then "RidinwRaven" should disappear. Press B to exit cheat menu
Submitted By: Adam

Board witih Steezy - ChillinwSteezy
Submitted By: Dgtlkid

Go to any menu with options and go to cheats.
Type in buzzsaW
Submitted By: Banana Twist

Go to optoins from the main menu and go to "Cheats". Enter MegabOUnce case sensitive.
Submitted By: Mac

Enter BigsteeZ case sensitive in the cheats option.
Submitted By: Mac

Enter ZiPster case sensitive in the cheats option.
Submitted By: Mac

This cheat allows your boarder to grab some massive air when jumping. Below is the cheat:
Super Jump
From the main menu, select "Options", then "Cheats". Enter MegaLeg to enable super high jumping. A sound will confirm correct entry. Press B to exit back out of the menu.
Submitted By: Nate 735 (txb)