Read If you Dare - Grand Theft Auto: The Ballad of Gay Tony Cheats

After a lot of testing and reading... We finally received every Cheat - Tested and Approved 

Cheat: All Secret Locations

Head to the internet café (or wherever you can access the internet) and insert the URL www.whattheydonotwantyoutoknow.com. If inserted properly, you'll be brought to an in-game message board containing maps of secret locations in the game. Check it out!
James Gutierrez

Cheat: Change Weather & Time of Day
To randomly change the weather and time of day, break out your cell phone and insert the following number: (468)-555-0100.
James Gutierrez

Cheat: Spawn Cars
Any time you're outside, break out your cell phone and insert the following phone numbers to unlock the vehicles listed.
Annihilator (Helicopter) - (359)-555-0100
Cognoscenti (Car) - (227)-555-0142
Comet (Car) - (227)-555-0175
FIB Buffalo (Car) - (227)-555-0100
Jetmax (Boat) - (938)-555-0100
NRG-900 (Motorcycle) - (625)-555-0100
Sanchez (Car) - (625)-555-0150
Super GT (Car) - (227)-555-0168
Turismo (Car) - (227)-555-0147

James Gutierrez
Cheat: Weapon Batch 2
To unlock an AK-47, knife, Molotov Cocktails, pistol, RPG, sniper rifle and Uzi, insert the following number into your cell phone: (486)-555-0150. Keep in mind that this will disable your ability to acquire some achievements.
James Gutierrez

Cheat: Adjust Your Wanted Level
To get rid of Niko's wanted level, insert the following number into your cell phone: (267)-555-0100. To add stars to Niko's wanted level, insert this number instead: (267)-555-0150. Keep in mind that this will disable your ability to acquire some achievements.
Mr-Pants

Cheat: More Cheats
Enter the codes below on your cellphone to spawn the desired vehicle or activate a cheat (entering codes will disable Achievements).
Floater - 938-555-0150
Akuma - 625-555-0200
Vader - 625-555-3273
APC - 272-555-8265
Buzzard - 359-555-2899
Bullet GT - 227-555-9666
Parachute - 359-555-7272
Super Punch - 276-555-2666
Explosive Sniper - 486-555-2526

James Gutierrez
Cheat: Refill Health, Armor & Ammo
To refill Niko's health and to give him some fresh armor, insert the following number into your cell phone: (362)-555-0100. If you want to give him health, fresh armor and refill all ammunition, insert this number instead: (482)-555-0100. Keep in mind that this will disable your ability to acquire some achievements.
James Gutierrez
Cheat: Weapon Batch 1
To unlock a baseball bat, grenades, M4, MP5, pistol, RPG and sniper rifle, insert the following number into your cell phone: (486)-555-0100. Keep in mind that this will disable your ability to acquire some achievements.
AngryMexicanGuy
Cheat: The Ballad of Gay Tony Weapon Pack
Call 486-555-0100 for the following weapons:
Knife
Advanced Pistol
Explosion-Pellet Shotgun
Silenced P90
LMG
Advanced Sniper
Grenade Launcher
Sticky Bombs

Unlockable: The Ballad of Gay Tony Safehouse Items
Peform the actions below to unlock the following safehouse items:
Parachute - Complete all 20 base jumps
.44 - Complete 10 gang wars
Advanced MG - Complete 20 gang wars
Explosive Shotgun - Complete 30 gang wars
Gold SMG - Complete 50 gang wars
Sticky Bombs - Complete 40 gang wars

Unlockable: NOOSE APC in The Ballad of Gay Tony
Kill 50 seagulls to unlock the Noose APC at the construction site.
Unlockable: No Ammo Cap in The Ballad of Gay Tony
Beat the game with 100% completion to unlock an infinite ammo cap.
Jorge Limon
Hint: Access Used Cheats Easily
Almost always, when you enter a cheat into your cell phone, you can access it automatically from the phone's main menu ("Cheats"), so you don't have to enter these obscure phone numbers more than once.
Logan Callahan
Hint: Easy Health and Armor Boost in The Ballad of Gay Tony
Once you have unlocked base jump challenges in TBoGT you can start a base jump challenge to refill your health! Go back and do it again and you'll have full armor.