The GFCC, having made a name for itself by churning our Gameshark codes for both GTA3 and Vice City, is awakening. With the PS2 release having a comfortable exclusive, the GFCC guys will have plenty of fun making all kinds of wicked Gameshark codes for you.
Have a look around their San Andreas hacking forum for all kinds of codes ranging from stamina to weight to spawn any car you like.