I find this particularly amusing to watch.. Enter a Gym and point a gun at one of the boxers, the other boxer will continue to lay into the boxer with he's hands up. After a while he will lower he's hands for about one tenth of a second then raise them again. Also, use the Jetpack cheat [L1, L2, R1, R2, Up, Down, Left, Right, L1, L2, R1, R2, Up, Down, Left, Right] while in the gym and fly over the top rope of the boxing arena. Both boxers will stop and head your way, so just smash the both of them.