I recommend a flight to Grand Canyon if you have never been there.

I strongly recommend, as did Travis, Red Rock Canyon -- a beautiful, nearby, easy trip. It is just 15 miles west of Las Vegas via Charlston Blvd. When you get there be sure to stop at the vistors' center where there are exhibits, and maps of the one-way self-guided auto tour of the loop through the park. There are a dozen or so designated parking areas just off the road at the best scenic view spots. Free admission. You could do the whole thing easily in about 2 hours from hotel and back, but allow more time. Be sure to take a lot of water bottles, and hiking boots if you want to walk the marked trails there.

Robt.