OK, near space. Hundreds of paper planes made by students were released from a balloon 36.5 kilometers up. Sponsor Samsung put an SD card in each plane. Planes have been reported in widely scattered locations, but it will take a while to figure out all the reported landing sights and claim a record for the longest paper plane flight ever. The planes, of waterproof paper, have been reported as far afield as South Africa, the United States, and Russia. Project Space Planes, led by Joel Veitch, built the aircraft and hope some may be found centuries from now - they may function as time capsules as well as messengers.
Correcting my initial post, I swtiched the title link to a batter and more recent article. I oritingally wrote the planes were constructed by German students, but I skimmed the article too quickly. It's still a unique and fascinating experiment.