Reminds me of a friend of mine.... WAY back, he had a Goldberg Eaglet.. and he used to try differnet wings on it.. I think he rubber -banded a butterfly wing on it, and also a 30" or so wing from Ace (foam wing) on it.. I'd be tempted to do stuff like that on cheaper planes than the Eagle

IMO

...but it would look cool

and confuse a lot of people