@Walter Hinteler,
I believe the first, and best, example would be the Soviets. A revolution, yes, but they initially tried to implement socialism. Worked for them, too, until Stalin, wouldn't you agree. From each according to his ability, to each according to his contribution, right?
I believe it was Lenin who said socialism was just a step to communism?
Others? Cuba, Cambodia... And wouldn't you agree Venezuela is on its way, as soon as it appears Chavez will lose his first election?
But I'm always looking to learn something about history and the world, if you have a different opinion?