As editor of Here's a story I didn't believe when I first read it: a Canadian inventor who calls himself Mr. Widget wants to build a rocket out of pop bottles that he can launch into orbit.
I guess I've been missing out, because I'd never seen a rocket made from 2-liter PET bottles fly through the sky. But judging by the number of related videos on YouTube, quite a few people do this sort of thing all the time. Apparently it's simple enough for a kid to build, and you can launch it in your own back yard. It looks like fun.
Ken Schellenberg, the chief executive officer of AntiGravity Research Corp. in Chilliwack, British Columbia, wants to take the concept to new heights. He already owns the current altitude record for a pop-bottle rocket (1,243 feet, according to this story on his Web site). Now he is developing a rocket that he hopes can orbit the earth. The story's not specific, but it mentions that the model he's currently working on could reach an altitute of about 5 km., which would certainly stay aloft for a very long time, although it's debatable whether you could say it's actually "in orbit."
Schellenberg sells kits for the public to make their own pop-bottle rockets, and he says they make great tools for physics teachers. I also found a fun section of the NASA Web site with information about bottle rockets, including instructions on how to make your own.