It is possible to move barrels without the use of Tiny. Simply line up the barrel between your commando and the spot you want it, then click on it repeatedly to keep the motion going. It may take a little practice but is nice once you are good at it.
Invisible to Enemy
First type 1982gonzo: (don't forget the colon) while playing the game. Then type Shift + V to activate the code.
Invincibility
Type "1982gonzo:" and then press Ctrl-I.
Instant Movement
First type 1982gonzo: (don't forget the colon) while playing the game. Then type Shift + X to activate the code.
Move Occupied Enemy Tanks
First you have to move a barrel over to a tank with the spy by walking in front of it to push it. Next, when you have moved the barrel by the tank you must place the tank between the object you are pushing the tank toward and the barrel, now you just push the barrel and the tank goes with it ! Use this cheat when playing missions 12, 6, and 18, 20.