I'm not sure of the exact Nevada/Las Vegas laws regarding porn production but there have been recent articles in the Las Vegas Sun basically welcoming the porn industry here.
http://www.lasvegassun.com/news/2012...oducers-las-v/
Interesting quote:
?We don?t issue permits? for porn productions, said Ed Harran of the Nevada Film Office. ?But if you shoot on private property, you don?t need permitting.?