Baseball? Count me in. After travel, baseball ranks a solid #2 on my priority list! Even though I have a self-imposed ban on attending games at Wrigley until the Cubs act like a professional team, I would make an exception for a FT event.
I'd be very interested in scenarios that had two games in two afternoons in nearby cities. Dodger Stadium and PacBell come to mind, as do Yankee/Fenway, Camden/Jacobs (thanks to Southwest), and Wrigley and the new Miller Park in Milwaukee.
That way, the real baseball fanatics could go to both games and pick up some extra miles, and people in two different cities could hook up for dinner the night before and catch one game the following afternoon.