<blockquote>Ramps were not the only means available to the pyramid builders. Making them and removing them would have been an enormously laborious process. Also, dragging the blocks up a lengthy ramp would have taken far more effort than using levers to move them straight up the face of the GP. The levers are feasible--they can lift loads like the limestone blocks. And though there is currently no explicit, physical archaeological evidence of them, clues from Herodotus and the ancient use of the shadoof hint that they were not unlikely. Also, the GP itself is unusually void of hieroglyphics or decoration, suggesting that the builders may not have left such evidence.</blockquote>
via <a href="http://www.ling.upenn.edu/~jason2/papers/pyramid.htm">Untitled</a>.