According to French architect Jean-Pierre Houdin, the mystery of how Egypt built the Great Pyramid has been solved--- they used a spiral ramp built from the inside to move the huge stones into place. Houdin recently presented his findings along with a 3-D computer model. For more, see this AP article(1).

1. http://seattlepi.nwsource.com/national/1501ap_france_pyramid_theory.html