Start a Proquest, then select your rider. Next at the bike selection screen press:

UP, LEFT, UP, DOWN, UP, RIGHT, LEFT, RIGHT, CIRCLE.

Now you'll be able to select any bike. *Note: You'll have to re-enter the code everytime you reselect a bike.

Start a Proquest, at the rider select screen press:

DOWN, DOWN, LEFT, RIGHT, UP, UP and CIRCLE.

Now you'll be able to select Slim Jim from the list of riders.

Beat the game with these characters to unlock hidden movies located in the game.

Dave Mirra	Dave Mirra Movie
Ryan Nyquist	Ryan Nyquist Movie
Slim Jim	Promotion for an online contest.
Amish Boy	Short movie of Programmer.

Start a Proquest, select your rider and then select your bike. Next at the style selection screen press:

LEFT, UP, RIGHT, DOWN, LEFT, DOWN, RIGHT, UP, LEFT, CIRCLE.

*Note: You'll have to re-enter the code everytime you reselect a bike.

Beat the game with all 10 original riders. This will unlock the Amish Boy.

By beating the game with any rider other than Dave Mirra, Ryan Nyquist or the Slim Jim guy, you'll unlock hidden features of the game. After earning a hidden feature you'll be able to view your cheats in the Cheat Menu. You can find the Cheat Menu in the Options menu. Below is a list of Riders and what they unlock once you've beatin' the game.

Troy McMurray	Exorcist Mode
Mike Laird	First Person View
Chad Kagy	Bike Suspension Mode
Tim Mirra	Silly Grunt Mode
Kenan Harkin	Sticky Crash Mode
Shaun Butler	Night Vision Mode
Leigh Ramsdell	Big Crash Mode
Joey Garcia	Ghost Rider Mode

Use the secret bike and perform a Double Peg Stall anywhere in any level. The longer you are able to balance the rider the more points you'll acquire. I mean it to, you can balance forever and collect hundreds of thousands of points even millions!

Start a Proquest, select your rider, select your style and then select your bike. Next at the track selection option press:

LEFT, UP, RIGHT, DOWN, LEFT, DOWN, RIGHT, UP, LEFT, CIRCLE.

*Note: You'll have to re-enter the code everytime you reselect a bike.