Funny noises
Play in the Back-Alley Ball Court with any team. Go to the right end of the court and listen after turning off the commentary voices.

Unlock New Characters
At the team select screen, go create a custom player and put these names on the custom player menu. Left mouse click the DONE button twice to unlock that character.

LEMON BOY - Thor Herring
BARRY DEJAY - Barry Dejay (duh!)
KOBE - Kobe Bryant
SHAQ - Shaquille O'Neal
VINCE - Vince Carter
MJ - Michael Jordan
ALLEN IVERSON - Allen Iverson