I have checked on line to find out what large trade shows are in whatever city I am visiting (you can find that through city.net) and then called the hotel and asked for the special rate attached to the show. When there is a major show at McCormick or Javitz, they will have made discount hotel deals with most major hotels.

Of course you can always play dumb and say, "My boss asked me to check for the AAEIS (or whatever) rate, but I don't know what those letters mean." Then they will start going through the list and ask you if you mean American Association of Elongated Insect Society, to which you say, "Oh yes that's it!"