The Burlesque Hall of Fame is a little hard to find, and as of 4/7/12 the phone number listed goes directly to the out-of-state voice mail of a woman who (I guess) used to work there.
It's worth finding, though, especially if you are interested in Burlesque or just looking for something "different" to to in Las Vegas.
Like other reviewers have mentioned, it's tucked inside the Emergency Arts building (which used to be a J.C.Penney's) where there are also lots of little gallery spaces, artsy work spaces, and a coffee shop.
It's free, but make a donation if you can...it's a good cause and they seem like they could use the money!
There are tons of interesting photos and some costumes exhibited, and T-shirts and postcards to buy.
The gentleman working there was very friendly and seemed to know a lot about the history of Burlesque. He was very passionate about it and took a refreshing feminist stance in talking about the subject.
The downtown/Fremont street area is pretty seedy & run-down looking during the daytime...I found it very interesting to drive around down there and see a side of Las Vegas that's pretty different from the Strip.
I'd say it's worth a little trip down there...there's metered parking on the street, you can check out the Burlesque "Museum" and then have a nice latte' and a snack at the little cafe.