Picture water skiing, except without liquid. See it here.
In 2001, Mike Ball (the columnist) won the Washtenaw County, Michigan, Mastercraft Indoor Doubles World Championship. They seemed dressed for Vegas. The site even has a 4.7MB QuickTime movie of the couple in action.
As oxymoronic as it first appears, the idea behind dry-land waterskiing competitions is to keep up the skills all year where weather does not cooperate. The couple are or at least were members of the Whitmore Lake, Michigan, Water Ski Club.
The report on the contest reads that, "They performed a 5-minute dry land 'Adagio Doubles' routine, which is similar in style to pairs figure skating.