In late April, timeshare giant Fairfield Resorts topped the half-million-member mark, a first for the industry. The company's ownership base has more than doubled since 1998, reflecting the growth rate of the timeshare industry as a whole.

Orlando-based Fairfield, a unit of Cendant Corp., started 39 years ago with a sales office in a converted gas station in Arkansas. The company's first project was a 14,000-acre master-planned resort in the Ozark Mountains.

Today, Fairfield has more than 70 properties in 21 states and U.S. territories. In 1991, the company was one of the first in the industry to move from traditional fixed-week ownership to a points-based exchange program.