If you get the chance go to the Grand Canyon - it's one of the few places that is hyped up so much you figure it is bound to be a dissapointment - but then it still manages to take your breath away!

I have also spent days just walking up and down the strip in Los Vegas seeing what crazy buildings we can create when we have the motivation/inclination.

I am a bit weird as I also enjoyed a walking tour around the old buildings of LA (see my web site, which I admit, could do with  refresh)

http://apps.webservicesuk.com/fromthemalverns/

(go into map view, zoom out then over to LA and zoom in)