Great site! I was in Vegas the other week and did a little "watching" outside the gate to the "Janet" terminal parking lot. Snapped a few pictures if you're interested. A few shots of the white and red planes you've seen before, one of them rolling down the runway.
Moreover, I found the Janet "arrival and departure" times are still pretty accurate on your site. I showed up just after 3pm on a Tuesday (3/4/08) and caught the last few people getting off a Janet plane about the same time the one in my picture taxied down the runway for take-off. As those people hit the parking lot, the cars started streaming out of the secure lot onto Have St and turning right onto Four Seasons Drive behind me to head to the Freeway. I got a decent look at most of the people coming out, too. I'd say the plane load consisted of: 95% males, appeared mostly between the ages of 30 - 45, very little facial hair, other than occasional mustaches, short hair, and fairly "fit" (as much as one can tell from the pectorals and up.)
Later I saw a JANET plane land about 6pm and another take off shortly thereafter.
I found a good place to park your car and watch the planes board and de-board. From Las Vegas Blvd, turn onto Four Seasons Dr (away from the Four Seasons Hotel). That road dead ends and you'll see the "Janet" parking lot and terminal just to the left behind the chainlink fence. From the end of Fours Seasons Drive, you can only go left or right onto Haven St. Turn left, then pull off onto a gravel shoulder on the right side. You can get a decent view of the Janet planes as well as people getting on and off them. If I had good binoculars, I could have gotten a good look at the faces of people getting off the planes and matched them with people I saw driving past me as the "rush hour" crowd departed the airport.
I also drove down Haven St and turned right onto the end of Hacienda Ave, which goes into a "private" area of airport/aerospace offices adjacent to the north side of the Janet terminal. This road dead ends behind the "new" Janet hangar building. I snapped a few shots of the white and red planes, while getting a few looks from workers standing outside the other offices there. No doubt I'm not the first guy they've seen take pictures like that.