On the south end of the strip there is a free monorail that links the Excalibur, Luxor and Mandalay Bay. One note on this is that if you travel from Excalibur on the monorail south it does not stop at the Luxor it continues directly to the Mandalay Bay; and only stops at the Luxor on the return trip or northbound trip. My suggestion is if you are going from the Excalibur to Luxor walk through the connecting mall instead.