It was pretty cool when I was in Jr. High School that there was an actual rocketry class that I took. Yes, I did get an A+ in the class. Duh!
Mr .Balfour also had a competition to design a rocket that would stay aloft for the longest time with a wimpy little "A" sized motor. All the other guys in the class were building boost gliders, multi-staged monstrosities and other fancy things. I mad a simple rocket, big fins, no paint, an 18" chute lubed up with talcum powder to open fast. I won the $10 credit toward any Estes model (I paid an extra $2 and got the Mars Lander with the fancy shock absorbing landing gear) when my wee little rocket stayed up for a whole 24 seconds.
Anyway, I came across this photo essay from about some high school teens in Spain that built a helium balloon with a camera payload. The balloon reached an altitude of 30,000 meters (about 19 miles!) before dropping the payload back to the ground 38 km away after just over 2 hours. What fun! Where do I sign up for this class?