NBA 2K3 cheats and cheat codes for Playstation 2

Go to the options menu after choose "Gameplay". 
Hold D-pad Left + Left Analog-stick Right and press Start. 
This will unlock the "Codes" selection in the options menu.
After enter the following case-sensitive codes:

3 bonus teams: Enter MEGASTARS
Trash in the streets: Enter SPRINGER
Black and white Graphics: Enter DUOTONE

Different entrance:
At the screen where all the NBA teams are shown, press 
Triangle, Circle, X, or Square to see a different entrance.

Easy lay-up
While doing a dunk, push Square in the air to do an easy lay-up.