In terms of size and attendence, the Los Angeles County Fair is considered the largest county fair in the nation.

NPR: A 'Histo-Tainment' Take on the L.A. County Fair

At the huge Los Angeles County fair in September, Levi Strauss will peddle a body-scanning technique that will allow fairgoers to find the perfect pair of jeans in 10 seconds, says Mary Ann Halford of the Fair Network, a company which arranges sponsorships.

ECONOMIST: State fairs