Go to the Options Menu and select Enter Cheat.

Password Effect
shoppingspree - All Peak 1 clothing.
naturalconcept - All artwork unlocked
graphicdelight - All boards unlocked
biggerthank7 - All peaks unlocked
djsuperstar - All playlists songs unlocked
postnobills - All Posters
nogluerequired - All Toys
gotitgotitneedit - All Trading Cards
notsosvelte - Svelte Luther
bronco - Unlock Luther
worm - Unlock the Eddie skin
myeyesaredim - Unlocks all videos
wheresyourtail - Unlocks Bun San
greatwhitenorth - Unlocks Canhuck
tankengine - Unlocks Churchill
milkmedaisy - Unlocks Cudmore
boneyardreject - unlocks Gutless
slicksuit - Unlocks Hiro
brokenleg - Unlocks Jurgen
back2future - Unlocks Marty
callhimgeorge - Unlocks North West Legend
betyouveneverseen - unlocks Snowballs
windmilldunk - unlocks Stretch
zenmaster - Unlocks the Brodi skin.
finallymadeitin - Unlocks Unknown Rider