Zepps, at the recently cited Dannysoar site, contains plans for not one but TWO stick-and-tissue free-flight model zeps. Ah, lovely.
Dannysoar’s stuff is absolutely top-notch; it’s even somehow appropriate that the site employs aggregational navigation.
UPDATE: Oh my God. Le Gyroptère, a mono-wing helicopter aparently modeled upon the flight technique employed by maple seeds. Amazingly, copious documentation of this incredible thing exists.