Compressed Air Rocket by Rick Schertle. Page 104. Blow your friends away as you send this 25-cent rocket hundreds of feet in the air. You can build this easy launcher and rocket with common hardware store items in an afternoon. Read Compressed Air Rocket in the MAKE digital edition.
Well, yes - this is very impressive. I watched the free "making" video and the "in-action" video. Lots of cool stuff. But compare that to this -something you can make for pocket change:
And - watching the video, I can't say the results are significantly different from the low cost version.
Reminder: Excellent information and instructions for these are here: http://www.sciencetoymaker.org/airRocket/index.html