Most cruise lines, eg P&O, Cunard etc operate cruises to Port Said, where you can vist the pyramids and Cairo. However, it is quite a long day - around 2-3 hours each way. Can't do Valley of the Kings in a day as it is too far from the coast.
Try Thomson's Red Sea cruise which has an excursion to Luxor I believe. A long day trip though.
I'm afraid that there isn't a cruise line that sails from a UK port to Safaga, the port for Luxor and the Valley of the Kings. You must therefore face up to either flying to Sharm el Sheik and connecting with the Thomson Celebration or flying to Luxor and picking up a Nile cruise (choose 5 stars or better). Ingle of Rugby is wrong - the Celebration does day trips to the Valley of the Kings, the Statues of Memnon and other sites in the vicinity including the amazing Temple of Karnak. It's a very long day (10 hours total on the bus) but honestly worth it.