You want to create an airplane? Quickly? Then look no further than the folks at Scaled Composites. The Adam M309 plane featured here was taken from initial concept in May 1999 to first flight in March 2000. Yep, 10 months from paper napkin to 5,000 feet.
Check out this article to see a potential future product of the personal transportation market. Toyota apparently is investing heavily in small aircraft research like this, the aim being to eventually produce planes for around the same price as cars.