When I was in the sixth grade I had a teacher who turned me on to these 3D paper airplanes. I can't remember the teachers name, now that I am writing about it. It will come to me....
It only took me a few minutes to find what I was looking for on Google. Being I was off yesterday and looking for something to do. I printed a couple off and started cutting and gluing them together. Building these two took me about three hours total.
If you would like try your had at one of these you can visit: http://users.ece.cmu.edu/~koopman/airplanes/
Once they were done I sprayed them with a clear satin urethane. I figured this would help with adhesion as well as strengthening the whole structure. I have about four more plans for different types of airplanes. I think they will look pretty cool hanging in my office or shop.