Many thanks to edisoncarter who seems to be at the forefront of a cheats revolution here.
Infinite Lung Capacity|
Swim underwater and never have to worry about drowning!
A Dozer will drop in your vicinity.
Gangs Control the Streets
Streets deserted except for gunmen fighting in the streets. No cops or regular citizens. No traffic except in gang territories.
No peds and only an occasional car on the street. Parked cars still spawn. Great for cruising. Still enough cars that you're not totally stranded if you wreck your ride.
Just like those early preview screens they released, like the one where Carl has a giant hand. This cheat locks the clock at 21:00.
For minute-to-minute progress check the topic on our own GTA Forums.