Access the nokia cellphone in the "extras" menu and dial in these cheats.

(714)555-8092         Master code
(949)555-6799         All surfers
(619)555-4141         All boards 
(702)555-2918         All suits
(328)555-4497         Level select
(213)555-5721         Great Balance              
(877)555-3825         First-person mode    
(818)555-1447         Trippy mode          

Thanks to Revolution readers Passionfly and Thundar1010!