At least one of my occasional readers is interested in homebrew musical instruments. Having listened to the example mp3's, I'm not sure that these instruments qualify, but here are instructions for building a tuba and other instruments out of plywood. The overall tonal quality makes you pine for the melodic sounds of the bagpipe and the didgeridoo.
The author, Paul Schmidt, also has some other interesting bits, like these plans for a model trebuchet.
For those of you seeking a slightly more melodious instrument, you could always try making a flute from PVC.
Addendum: Check the comments to this posting for additional comments from their creator. He makes the following points:
The instrument is a reed instrument, not a wind instrument, hence my comparing them to a "tuba" is inaccurate.
The mp3's he did were literally the first sound made by the instruments, and it is unfair to judge them on that basis.
I should avoid glibness when describing other people's passions. 🙂
Lessig had this link awhile ago on his weblog, but I thought it would be appropriate for Independence Day. You can purchase a copy of The United States Constitution and Amendments from Amazon, formatted for Microsoft Reader. Interestingly enough, it's protected by DRM, so you aren't granted any rights to redistribute, alter, or even print the book, despite its public domain status. As one of the reviewers hinted, it may be worth the $2.99 they charge just for the irony of it all.
Of course, if you don't wish to invest in irony, you can thank Project Gutenberg for providing The Constitution (even formatted for the Pocket PC) and The Declaration of Independence, which was Ebook #1, and initiated the idea of Project Gutenberg way back in 1971.
To all my readers, have a happy Fourth!
Addendum: You can also get a fairly high resolution scan of the Declaration from ushistory.org.