I took Swiss Air from London to Zurich (~90 min) and then transferred for another flight to Cairo (~3.5h).
Upon arrival in Cairo, I immediately took a sleeper train to Aswan (the other end of the country).
After a day in Aswan and a day trip to Abu Simbel, I took the train north to Luxor/Thebes/Karnak.
Three days later I took a sleeper train back to Cairo to explore the Cairo Museum, Giza and Saqqara.
Map from http://geography.about.com/