They still have them and they are still big deals, they're called Expos now. Unfortunatly it takes many years for them to get to a country where you'll have easy access to them.
http://en.wikipedia.org/wiki/Worlds_fair
Here's a list of some of the world fairs in the past and the ones to come in the future and their locations:
1974 Spokane (United States)
1982 Knoxville (United States)
1984 New Orleans (United States)
1986 Vancouver (Canada)
1988 Brisbane (Australia)
1992 Seville (Spain)
1993 Daejon (South Korea)
1998 Lisbon (Portugal)
2000 Hanover (Germany)
2005 Nagoya (Japan)
2008 Zaragoza (Spain)
2010 Shanghai (China)
Like the Olympics, countries bid for the right to host the world's fair.