A lot of clubs will make a limbo event the last one of the day. It normally causes several crashes. We decided to keep the height at 10 ft and give each pilot 5 attempts , so there were 5 possible "scores" to be made by each pilot. Amazingly, there was only one crash. It takes the fun out of the fun-fly to go home with balsa dust.
On the other hand, Hitech ran an event for electrics last year in San Diego and used razorwire instead of a ribbon. Word was there was a huge pile of foam at the end.
Depends on your defintion of fun, I guess.
We also let our newbies that were still on buddy boxes participate. When the "instructor" took control, timing, or counting stopped. They weren't competitive, but they had a ball.
JR