Yes, we flew as it was by far the most convenient and cost effective both in time and money.
From Cairo, we just hired a taxi for the day to see the pyramids, and did the same for the older pyramids further south.
If you get the chance, take a taxi from Luxor and head north for about 3 hrs to the temple of Abydos. about 6 years ago
You have two options to get from Luxor to Giza either by sleeper train but then you have to spend 2 nights in the train but this is cheaper than the flight.
The second option you can take the flight. Many travel agencies provide day tours to Cairo by flight including lunch and you can get good rates from them
http://www.egyptholidaysdirectory.com about 6 years ago
It's about 9 or 10 hours from Luxor to Cairo by train. (It is inconceivable that it would take two nights to get there, unless the train breaks down.) From the train station, you can take the subway to the Giza subway station, and catch a taxi. about 6 years ago