After walking the strip for hours, but still wanting to sightsee... the tram is your answer! Free ride to and from Excalibur/Luxor/Mandalay.
Too bad that it only services those 3 hotels, but its better than nothing. Another unfortunate thing is that it closes early. I think the last ride is around 10/10:30pm? I could be wrong, but I'm pretty sure its 10-something.