Well, I'm personally of the mind that the Giza pyramids were built by a technological civilization, not that we think of as Egyptians today ~ those people moved into the area much later, and restored some of it, and copied the style of architecture somewhat, but were unsuccessful (in some cases, very) at building any pyramids of their own.
For one thing, the north wall of the Great Pyramid is so lucky to coincide with the 30th parallel, and all three are lined up more specifically with the cardinal points than we have been able to duplicate today. The whole Giza complex was obviously planned by a great and thoughtful people and for a specific purpose that we have not been able to specifically describe today.
That these buildings might've been designed purely as tombs is ludicrous, though I don't doubt that it was the reasoning of later kings that immortality might be achieved through declaring such internal chambers their final royal resting place.
Also, there is the pyramid energy thing. Somehow, be it magnetism or whatever, if you place your razor under a pyramid of a certain slope and lined up to magnetic north, it'll stay sharp enough to shave with for over a year. I've seen this happen, and also seen people get sick by sleeping under pyramids made of plastic, not glass or cotton sides.
Such a "magical" trait is unlikely to be coincidentally happened upon by tribes of recently civilized nomads. But if they discovered this somehow, it would explain a great many things about their most anomalous religion.
There are pyramids all over the world, and all are pretty much from the same antiquities era, yet modern science tells us that these societies couldn't have had any contact with each other. I mostly agree with that supposition, at least as far as the pre-modern era goes, but there is an obvious common inspiring source with all of them.
I feel that this must be the famous Atlantis, which has gotten its share of bad press (especially lately), but such a society as described to (and/or by) Plato has been reasoned in recent years to have originated on the continent which we now know of as Antarctica, in such extremely ancient times that the continent was only partly covered by snow and ice. Such a people would have considered "the one true ocean" to be what we now separate into three (Indian, Atlantic and Pacific). And it would have been a short seaward journey to the continents of Australia, Africa, and South America, (the latter two being ultimately considered part of the same major land mass, as per Plato's tale, as they are all connected together eventually, especially if there was less water in liquid form those many thousands or even millions of years ago).
In the Americas, pyramid complexes line up to the planets in our solar system, and there's even an extra one miles out from the main group (in the jungled hills), possibly representing the fabled Planet X that we have yet to discover. But merely suggesting that these were created by anyone other than savages (in grass skirts or some such primitive garb), will send a scientist over to your house in the middle of the night to paint nasty messages on you door with a small hand-held laser. And don't you dare mention the "A" word, unless you have the time and inclination to be ripped to intricate shreds by snobby, stuffy know-it-alls. Atlantis, Atlantis, Atlantis, Atlantis, Atlantis !
There are also tons of clues pointing to the possible antiquity of these megalithic monuments, not the leastof which being the type of weathering erosion that the Sphinx had endured and nearly succumbed to. The Sphinx points east exactly to the constellation Leo in the era of 10,500 BC, when coincidentally, the Milky Way lines up with the Nile River, and the three main Giza pyramids line up with Orion's Belt, and another pyramid (I forget the name) lines up with Betelgeuse or Aldebaran or some other such star in that sector of the sky. The star Sirius, (only 8.8 light years from us ~ relatively next door) plays very significantly in the Egyptian religion, and that the Egyptians we know of worshipped this star as the goddess Isis, to me suggests that they knew something that we do not about all this, but still had no clue as to it's true implications.
The gods they speak of, (and many other religions all over the world as well) may just be our stellar neighbors, and besides being technologically advanced, may have more than just a passing interest in our planet and star system.
The constellation Ursa Major (The Big Dipper) is known in Chinese mythology as "The Government." All of the major recognizable naked-eye stars in this formation are really very close to us as stars go at 30-40 light years (and even closer to each other at 8-20 light years), and of the same general spectral type too, (Blue-White Sub-Giants I think).
The Cydonia Plateau on Mars has what seems to be a face carved in stone, a mile high and four miles across, with some strange pyramidesque shapes ~ and a wall, perfectly straight and going on for several miles. This whole complex is mirrored exactly in Silbury Hill in the English countryside, near Stonehenge. An ancient road follows the path matching the wall on Mars, while the Tor corresponds to the face, and certain other structures follow the pattern as to the Martian pyramids.
All this leads my wandering mind to wonder if this system wasn't settled millions of years ago by an advanced Humanoid species and even if we are their descendants. The fabled Atlantis is said to have failed over a very long period of time, mostly due to greed and a general degradation of certain wise philosophies that had sustained it for so long, and even presumably evolved it into the grand Utopia it was supposed to have been in the first place.
One thing we have going for us though: satellites. Even if the whole world turned upside down in some sort of Armageddon like manner, we'd probably be able to communicate with each other somehow, even if we remained planetbound because of it for generations to come.
I welcome all sane distributions of logical thought on this matter, but will ignore callous out of hand dismissals out of hand. I'm looking into this mystery further because the more I read, the more it makes sense. Any scientific journals supporting this theory will be held in as high regard as if they were to say the world is round and orbits the sun.