A million monkeys is a bit unfair...
These people were actively thinking about the future, rather than just hammering random keys. Though admittedly, it can sometimes be hard to tell the difference ;)
There's plenty of other interesting nuggets out there, too.
EE Doc Smith produced some spectacular space-opera cheese; much of this was the cliche "hero saving heroine from Certain Doom with the power of Science", but his Lensman series included some interesting concepts and his exploration of how to handle complex space battles was cited as an key inspiration for the US military's development of Command Centre capabilities in World War 2.
Robert Heinlein produced some equally interesting stuff - the militry concepts and tactics in Starship Troopers are well thought out (and the way these were ignored by the film is a major reason why I despise it) - and along the way, he also invented things like waldos (named after his story) and the water bed; his story was actually used as an example of prior art when someone tried to patent the concept!
Keith Laumer is much less well known, but produced some interesting concepts, especially in his Reteif series, where a diplomat wanders the cosmos, cleaning up after his incompetent bureaucratic superiors. Admittedly, it's hard at this distance to determine how much was original and how much was drawn from other sources, but he dabbled with concepts such as virtual reality, remote-controlled robotic bodies and cloning. It's possible at least some of this was driven by the fact that he suffered a stroke which restricted his mobility.
There's many more out there - for instance, the British government ignored Arthur C Clarke's ideas about geo-stationary satellites.
Sadly, one area where the Golden Age of sci-fi seemed quite weak was around computing science (though again, EE Doc Smith did come up with the concept of "robot controlled" spaceships as the first line in massed assaults). I suspect this was down to editors/publishers not being comfortable with the concept (and/or assuming the reader wouldn't be interested); Science was there to be controlled, not self-governing!