Press up to access your cell phone and press up again to access the keypad. Unlock the following cheats by dialing the corresponding numbers:

CHEAT FUNCTION - PHONE NUMBER
Climate Change - HOT-555-0100
Full Armor & Health - 362-555-0100
Full Armor/Health/Ammo & Fix Damaged Car - 482-555-0100
Identify Songs on the Radio - 948-555-0100
Raise Wanted Level - 267-555-0150
Remove Wanted Level - 267-555-0100
Spawn Annihiliator Police Helicopter - 359-555-0100
Spawn Burrito - 2826-555-0150
Spawn Cognoscenti - 227-555-0142
Spawn Comet - 227-555-0175
Spawn Double T - 245-555-0125
Spawn FBI buffalo - 227-555-0100
Spawn Hakuchou - 245-555-0199
Spawn Hexer - 245-555-0150
Spawn Innovation - 245-555-0100
Spawn Jetmax - 938-555-0100
Spawn NRG-900 - 625-555-0100
Spawn Police Chopper - FLY-555-0100
Spawn Sanchez - 625-555-0150
Spawn Slamvan - 826-555-0100
Spawn Turismo - 227-555-0147
Spawn SuperGT - 227-555-0168
Weapon Package #1 - 486-555-0150
Weapon Package - 486-555-0100