Input help1nghand in the cheat menu.

Input sirius-DJ on the cheat menu to shred as Jason Ellis.

Input the_condor on the cheat menu.

Bails N' Burns 1 of 2 ... Clear Classic mode.
Bails N' Burns 2 of 2 ... Achieve 100% completed in Story Mode.
Dev-Team Skates ... Achieve 100% completed in Classic Mode.
American Wasteland ... Clear Story Mode.

Clear Story Mode (Easy)
Robot Tony
Mindy

Clear Story Mode (Normal)
Little John
Iggy
Jason Ellis

Clear Story Mode (Hard/Sick)
Jimbo
Murphy
Mega

Clear Classic Mode (Normal)
Billie Joe
Boone

Clear Classic Mode (Sick/Hard)
Mat Hoffman
Dave

Achieve 100% in Classic Mode
Master Zen
Hardhat Guy
Downtown Guy
Grafitti Guy

Achieve 100% in Story Mode
Baller
Welder
Camera Guy
Chloe

Clear All Skate Ranch Missions
Barber
Carnival Guy
Downtown Guy
French Guy

Clear All Gaps
Oil Rig Guy
Policeman
Street Performer
Boone