Enter these codes at the character select screen, press "del" and 
enter the name. Spacing on the codes may or may not be right.

            itsgallus: All Levels All Cities
            nineinarow: All Levels All Cities
            superwell: All Levels All Cities
            iamthelaw: No Police
            stevesmates: No Police
            itcouldbeyou: Gives You 999999999 Points
            suckmyrocket: All Weapons, Armor, & A Get Out Of Jail Free Card
            itstantrum: Unlimited Lives
            6031769: Unlimited Lives
            hate machine: Raises Point Values
            buckfast: Press the * on the NUMPAD and get all the weapons
            porkcharsui: Diagnostic Mode
            callmenigel: press * to get all weapons and 99 ammo (this can be 
            done repeatedly)
            iamgarypenn: ?
            iamnotgarypenn: ?
            davesworld: ?
            createorize: ?

            This is a real cool cheat. While you're in the game type DTA yOu 
            LoUsY PiEcE oF tRaSh then your guy will be able to punch windows of 
            the cars and beat those guys to the bloody pope