Take the Damn Tour hah on my list
Depending on Time and Money there are plane and or Helicopter rides that take you to the Grand Canyon , Hoover Dam and fly over the strip at night - on my list
Top of the Eiffel Tower at night is a must - they have holes in the steel frame to allow your lens to got through to get some shots.
If you are into vintage cars the Imperial Palace has a nice car show for cheap (think it was $6.00) some samples
Daacon Flickr Vegas Car Show
The South Side has newer buildings nice place to take pics day or night.
Caesars Palace Forum Shops just reeks of very expensive things !
Shark Tank at Mandalay Bay (very dark though tough to get good shots)
The strip day or night
The Venetian has some very neat photo opps
Man there are sooooooooooooo many places and opportunities to take pics there - my flickr site has a few others ....
Have a great trip !