Hidden Teams:

 To play as the hidden teams, press Left, Up, B, Up, Down, Up, Right, C
 at the title screen when the words  "Press  Start"  are flashing.  You
 should  hear a  quick  "clink"  when you enter the code.  Then, at the
 "Team  Selection" screen for any mode, scroll down until you reach the
 fraternity and other hidden teams.

"Taz" player:

 Pick any of the game modes and select a team.  At the Today's Match-Up
 screen, rotate  the  directional  pad  clockwise  for five seconds and
 press  any  button.  When  the  game  starts, your character will be a
 whirlwind that no player can touch.

Power dunks:

 Pick  any  game  mode  and  select  a team.  At the  Today's  Match-Up
 screen, repeatedly  press  Up and  Down for about  five  seconds, then
 press any button. When the game starts, you can make half-court dunks!