Yep, this ones real easy. You were a boy once. You know how to make a paper plane. Unlike back then though, there is this little invention of Al Gore's called The Internet:
(and many other sites.....)
Go crazy. They love it.
PS- My crew like to play a little game we call "The Blitz". You need a largish room. The Dad builds a slow lumbering glider type of paper plane (ie: the bomber, complete with Luftwaffe insignia), and the kids build pointy-nosed super-fast "jets". The Dad then stands on a chair and launches the said slow lumbering bomber toward the general direction of London (ie the other side of the room). The kids, who by this point have emblazoned their planes with patriotic national markings, launch as many fighters as they can to knock the bomber out of the sky while yelling "Tally-ho!!" (well, OK, they don't yet, but they will as soon as I find "The Battle of Britain" on DVD). There is no actual object to the game, but in true SGD fashion, usually continues till Mom gets home.
- we, the aeronautical challenged, salute you