I originally heard about the Atomic Testing Museum from a climbing friend, but hadn't given it a second thought until I realized it was less than a block from my hotel. I didn't bother with the Area 51 option, which seemed kind of cheesy.
The museum is packed full of artifacts and information, from scientific to historical to pop culture. They do a excellent job of taking you though the current events of each decade and the corresponding changes in the use/testing of and attitudes around nuclear technology. Also of highlight were the some of the ancillary technologies that arose, such as the amazing high speed photography developed by Harold Edgerton (http://en.wikipedia.org/wiki/Harold_Eugene_Edgerton). Sadly, I only had an hour, but I am definitely planning to head back.
Helpful hints:
- Video cameras are not allowed, but still photography is.
- They have aluminum and plastic recycling bins, something in short supply in Vegas.