I read this thread sometime ago, and remembered seeing how to make a $12 Ukelele on a site, somewhere. Well today, I finally came across the site again. "FolkUrban". It describes how to make a $12.00 Uke, a $5.00 Clarinet, a toilet ocarina, and the list goes on and on. Some real fun stuff. The link is here:

FolkUrban and the $12.00 Uke

and here is another general link on instruments in general that includes making musical instruments.

Instrument sites from aj-glass

JAB