I did the ACPNTS (Air Cadet Pilot Navigation Training Scheme) in 1994!
The fast jet boys on here may scoff, but when your a keen spacey at age 16 its a bloody brilliant 2 weeks!
You learn how to plan trips in a light aircraft (Bulldog in my day), rules of navigation (eg the 1 in 60 rule!!) etc, and then go off and fly the sortie. It was great at age 16 being able to tell my instructor (an ex Vulcan pilot) where to go!
The ACPNTS isn't as good as the Flying Scholarship, but I'd definately reccommend it if you can get one one, particularly if you have dreams of becoming a Nav/WSO!