John,

I've got to (respectfully) disagree with your comments about nothing to do in Vegas for kids. I will concede that there isn't a lot to do, there are still some great things for a kid to enjoy there. My son is now 11 and has been going to Vegas since he was 5.

Mandalay Bay has an incredible aquarium/zoo.
During the day, the strip has some great sights. I won't take my son on the studio at night any more because he's old enough to understand the flip card business.
The Ceasars shops have some entertaining fountain shows, it gives the kids something to see while you're wandering and shopping.

If you've got a car, the Hoover Dam, Red Rocks, Death Valley, Rhyolite and some great small towns are a day trip away. You can drive for 30 minutes from the strip and be hiking in some of the most beautiful desert scenery you can find. Make an overnight to Mesquite and zip up into Utah for a day of sightseeing and hiking in Zion near St. Georges.

M&M store...
The MGM lions...
Hotel pool...
Movie theatres
Bowling
Circus Circus
MGM Arcade
Free monorail between Mandalay and Excalibur.

One thing I have learned in traveling with The Boy is that it doesn't always have to be flashy and extravagant for them to have fun. A good blend of time at the pool, something to do (that doesn't have to be expensive) and some great dining experiences are all it takes for a kid to have a good time. If you add in a couple of age-appropriate shows (Cirque is always a good call) a trip to Vegas can be fun for everyone.