Select "Password" at the "Options" menu.

Code - Effect

JUSTDOIT - All Nike gear
SHOJIRO - Bridgestone items
SNAKEKING - Cobra items
JUSTSHAFTS - Grafalloy items
MACTEC - MacGregor items
RIHACHINRZO - Mizuno items
JANNARD - Oakley items
GUYSAREGOOD - Precept items
MRADAMS - Taylormade items
PROOFTHIS - Unlocks All Courses
GAMEFACE - Unlocks All Golfers