Xbox
Start a pick-up game and enter an ID. Now hold L and enter one of the following when the "Enter codes now" message appears at the bottom of the screen: 
 Infinite turbo: 
 X, X, Y, Y
 Big heads: 
 B, X, X, B. 
 Small players: 
 Y, Y, B, X. 
All courts:
 X, Y, Y, X 
All jerseys: 
 X, Y, B, B.
All quicks: 
 Y, B, Y, X. 
 All NBA legends: 
 X, Y, Y, B. 
 ABA ball: 
 B, X, B, X. 
 WNBA ball: 
 B, Y, Y, B. 
 Ball trails: 
 Y, Y, Y, X. 
 No display bars: 
 X, B, B, B.
Explosive rims: 
 B, B, B, Y. 
 No counters: 
 Y, Y, B, B. 
 Easy two pointers: 
 Y, B, X, Y. 
 Hard two pointers: 
 Y, X, B, Y.
 Classic Michael Jordan: 
 X, Y, X, X.
St. Lunatics team: 
 X, Y, B, Y.
  
Thanks to Revolution readers Kobeman, joe shmoe and Phillip!