Fast skater
In the middle of a game push the start button and type in the following code: Triangle, up, down, Circle, left, right. This code should alow your skater to speeds well above average speed to jump higher and stay in the air longer to improve your trick.

Unlock Special Skate Park: The Dream House
When you have opened the final skate area (Huntington) then place third or better in the competition to recieve a Dreamhouse in which wings of the Mansion can be unlocked by completing tasks from the courses (High Score, Hitting all of a certain object, ect).

Unlock Every Single Level
During play, pause the game and press Circle, Up, Down, Square, Triangle. All levels including the dreamhouse will now be unlocked

Unlock Every Single Trick
Press pause then press Down, Left, Up, Right, Down, Left, Up, Right. Then it should say "all tricks enabled". Also, it should say "dont hurt yourself".

Huntington level
To unlock level 8, go to the big gray ramp with a blue streak on the bottom that is in front of a wall. Go off the ramp, and do an air trick. If you hit the wall exactly in the middle of the trick, you will land the move perfectly and get full points.