LAS has two seperate runway systems, 1/19 L&R and 7/25 L&R. It has been hurt somewhat by the death of Reno Air, which made up a good amount of the traffic there, but Southwest and America West have stepped things up to fill the void. Vegas winds are unpredicitable, and runway directions will often change several times over the course of the day, but the 25's seem to be the most used. The facilities are exactly what you'd expect in Vegas...lots of lights, lots of noise, and LOTS of slot machines!
INDOORS:
-Concourse B, Gate B21: Great view of takeoffs on 19 or 25 and landings on 1 or 7. Windows in this terminal are REALLY tall, perhaps 20 feet tall!
-Concourse B, Gate B12: Another great place for the action on 7/25.
-Concourse A, Gate A18: A nice view of takeoffs in either direction on 1/19.
-Concourse C, Gate C12: The best place to see landings on 25, the most active runway. View is not terrific...parking garage is much better.
-Tropicana Hotel: Get a room on a high floor of the south side of the larger of the two towers (I can't remember if it's the Island Tower or the Paradise Tower) and you'll get a complete view of the entire airport.
PRE-9/11 SECURITY REPORT:
-Security maintains a strong presence in the parking garage, but they seem to be very tolerant of spotters. They are very easy to see...they ride bicycles and wear bright yellow shirts. Just keep an eye out for them and you'll be fine. Around the perimeter of the airport, security is not as tight. You can stand around the perimeter, which some people like to do on Eastern Ave. along the east side of the field, and security doesn't seem to mind.