Might be best to try a quick flight before the talk just to whet their appetite, just gentle, maybe the odd loop or roll. Then talk them through it, give them an idea of whats goin on, them blow em away with a full-bore freestyle routine on the deck. What do you mean by small 3d plane?

For your talk, don't get too deep into the construction side of things unless your talking about composites(lots of oohs and aahs), more on what control does what, how much G your pulling, maybe set up a foamy for them to move the controls themselves(always good to see some of the girls jump when they start the motor ).

Good luck dude

Spacewalker, thats nothing to do with kev, thats just plain nasty for the sake of it.[:@]