Last time I visited Las Vegas I made a point of braving the 100 degree heat (dry heat!) to see the Neon Museum located in North Las Vegas. It's a wonderland for neon lovers. The non-profit organization has collected the old neon signs as they are torn down in Sin City and stores them in a multi-acred lot.
You can set up a tour and photograph as much as you like. Many of the neon signs are sans neon tubing and they are weathered from the years which makes them more beautiful in my opinion. One of their more recent acquisitions was the Stardust sign which was in multiple pieces.
Here are some shots from my excursion.
You can find out more here.