GQ, mostly because I just learned about it in class today!
So, the short answer is: the pyramids were built by volunteers, not slaves.
The long answer:
At the time that the pyramids were built, they didn’t have slaves. You get slaves by conquering other lands (as well as the occasional debt slave/indentured servant, but certainly not thousands…). The Egyptians weren’t really going outside their own land at the time – if they had been, they would have brought back other technologies with them like, oh yeah, the wheel. That’s right folks, not only were the pyramids not built by slaves, they were built without the wheel. The thousands of stones were dragged hundreds of miles, without the wheel.
So how were they built? By religious devotees. The pyramids were built to be a tomb for the pharaohs, who were considered gods themselves, and it usually doesn’t hurt to be on the good side of a god. They were built on the off-season – when they weren’t harvesting or planting crops.
We also have some accounts of them being built that go against the idea of them being slaves.
Fun fact: The pyramids were originally cased in marble, which has now been almost completely stolen. However, at the time that they were putting the marble on, they’d graffiti it, often in the same vein as “The Red team kicks the Blue teams ass, because they’re 2 days behind – suckers!”
The temples started being built in the Middle Kingdom, because it was just too much money and time to create pyramids. This is when they start getting into the sphinxes, including The Sphinx (I don’t know the official name off-hand, but you know the one I’m talking about). I don’t know if they used slaves for it, as we haven’t covered it.