Are Humans becoming less intelligent?

In a way, yes and no. Increasing technology makes the population smarter. But, we're loosing common sense, especially in the western part of the western world.

With the amount of discoveries, inventions, theories and opinions put forward in the world everyday there's bound to be some that are incorrect or a bit out there.

There's a greater level of formal education available to people worldwide that at any past time in history and that generally leads to increased intelligence amongst the populace.

(I think Einstein) said something about he was only as intelligent as he was b/c he was standing on the shoulders of giants. We have a lot more knowledge (as far as I know).

We have 7 billion people (or so) in this world. You'd think there would be more Tesla's & Einstein's. But maybe it's b/c we have around 7 billion people we don't appreciate the genius of people like Steve Jobs, Bill Gates, the scientists at NASA and CERN, Stephen Hawkins, etc...

Not at all. Our love of technology has made us more intelligent. Brain size does not tell the tale about intelligence. The human brain folds, making it fit into less space. Cro-Magnon had the same size brain as us. They were early modern humans. Neanderthals had slightly larger brains, but based on the type of tools they used, it is assumed they were less intelligent.

Larger brains do not directly correlate with higher intelligence. It is the complexity of the networks within the brain, not the volume, that matters.

There is no way to measure how "intelligent" cave men were compared to us. They did have larger brains.