In November 2000, my wife paid for me to take a trip to Cairo for my birthday, with my brother-in-law who is doing a PHd in archaeology. This was a place I have always wanted to visit, and I was not dissappointed. Personnally, I think this is the most amazing place on the planet, and if you get the chance, visit the pyramids. You will not regret it!
Khufu's pyramid is open to the public, but only in very limited numbers due to the damage that has been caused in the past by the huge number of people that have explored the pyramid. We had to queue and wait for about an hour to make sure we got a ticket to enter the pyramid, but it was worth the wait. Only twenty people are allowed into the pyramid three times a day.
Cameras are not supposed to be taken into the pyramid but I managed to sneak mine in and take some pictures.