Black and Bruised
Unlock All Boxers
Select the cheat option from the setup menu and press the following: X, O, Square, Square, R1, R1, Square, O, X.
Alternative Costumes
Select the cheat option from the setup menu and press the following: X, R1, O, Square.
Invincibility
Select the cheat option from the setup menu and press the following: Start, X, X, O, R1, R1, Square, Square, Start.
Conversation Mode
Select the cheat option from the setup menu and press the following: Start, R1, X, O, Square, R1, R1, R1, Start.
Turbo Mode
Select the cheat option from the setup menu and press the following: Start, R1, R1, R1, R1, R1, R1, R1, R1, R1, R1, Start. (That's R1 ten times).
Constant Power-Ups
Select the cheat option from the setup menu and press the following: Start, X, O, X, O, X, O, Square, Square, Square, Start.
Unlock Intercontinental Tournament
Select the cheat option from the setup menu and press the following: X, X, X, O, O, O, Square, Square, Square.
Unlock Scrapyard Arena
Select the cheat option from the setup menu and press the following: O, R1, O, R1, X, X.
The database at Game Oak contains more information regarding Black and Bruised for Sony PlayStation 2.