In 2001, one of the premier theoretical CS conferences, Foundations of Computer Science (FOCS), held its meeting in Las Vegas at the Tropicana. Only about 200 people attend, but it was memorable:

(1) The conference hall right next to the FOCS conference room was hosting the international lingerie trade conference ! Still, the talks were more interesting and well attended.

(2) I, like many others, didnt gamble, but I watched my office mate from MIT (now a brilliant scientist who recently won the Godel Prize) lose his 40$ (a big amount for grad students back then) at the blackjack table in literally 3 hands (35 seconds).

He said, "I cant leave vegas without at least trying" and he proceeded to show exactly how LV works.