Nebuchadnezzar, I'll direct you to Captain Dave's posts. He wrote his thesis on the cause of World War I so obviously knows what he's talking about.

You saying all the sources of power were in the hands of the "allies" particularly aggravates me. It really shortchanges Germany.

I see where Nebuchadnezzar is coming from about the "sources of power" and changing the status quo. Britain, France and Russia all had had their glory days and had created their empires, now Germany had come of age and it wanted a piece of the action. From Germany's perspective the time had come to renogotiate the pecking order in Europe. It wanted to be the "alpha male" so to speak. Perhaps it was human nature that caused WW1?

I have a question though that someone more knowlegeable than I might be able to answer. Specifically, what was it that Germany was hoping to achieve in Europe? Was it just increased real-estate? Or was it hoping to destroy the military power of its rivals so that it could take over their colonies? Or something else?

Actually, Invictus, Nebuchadnezzar does have a point with his balance of power argument (and it's one that I'm pretty sure I read about somewhere). You are right, though, when mentioning that his argument short-changes Germany.
The main thing that probably just about negates N's POV (or perhaps it's just something designed to stir up extra discussion?), however, is that Britain would have preferred to ally with Germany, but Germany was doing its best to be Britain's rival rather than friend. Thanks to Queen Victoria, the two monarchies were related (George V and Wilhelm II were cousins in some form or other, possibly directly, I can't be bothered to find a family tree), which put Germany naturally ahead of France in terms of alliances, but the Germans were so keen to rival Britain (read about the Tirpitz Plan and German colonial ambitions [although the latter dates back slightly earlier] for more detail in this), that the two countries' relationship failed spectacularly.

@spyman, Unlike WWII, the motives for WWI aren't the most clear-cut. I'll happily admit to not remembering a great deal about this, but it was a little bit one of those wars-for-war's-sake-type wars. I think in the main, though, the problem was Franco-German tensions, and Germany's desire to be a major power on the world stage. Also, as a nation, Germany was still incredibly young (created in 1871), so it was still trying to find its natural place in the world.
You can't forget, either, that up until WWI, a war was seen as a good way to resolve diplomatic tensions - the winner(s) would probably gain what they wanted, and the loser would have to cede it. Sadly, with the weaponry that was invented in time for WWI, this changed warfare forever, meaning that diplomacy became limited to talk (and board games!).

It was Austria, of course, pouncing on Serbia!
Without that declaration of war signed by Franz Josef in Bad Ischl, the whole WWI tragedy conceivably (!!) might never have happened, in spite of all military-political muscle-flexing and jockeying which took place at the time.

Plus: Ironically, World War 2 was also started by a native son of Austria....