Here are a few more cheats for you to try.

Super Punch

Up, Left, X, Triangle, R1, O, O, O, L2

Gangs Members Everywhere

Similar to the 'Gangs Rule the Streets' cheat, except all pedestrians are replaced by gang members. Policemen, firemen, paramedics and shop owners stay the same.

Left, Right, Right, Right, Left, X, Down, Up, Square, Right

Funhouse Theme

strange cars have hydraulics. Pedestrians become fast food workers and clowns. CJ wears strange outfit.

Triangle, Triangle, L1, Square, Square, O, Square, Down, O

Sandstorm

Up, Down, L1, L1, L2, L2, L1, L2, R1, R2

Countryside Vehicles

L1, L1, R1, R1, L2, L1, R2, Down, Left, Up

a thanks goes out to edisoncarter at GTAForums for finding them.