I've thought about this before when I installed bamboo flooring in my basement... and then I was looking for a decorative piece of wood for backmounting some art recently... and bam, there it is again...
The plywood sheets linked above would be ready to go, no additional finishing needed... just cut and glue and they already look nice. Plus, they came in some pretty thick sheets. Bamboo is hard like a rock... It has more of a 'clack' sound when you tap it... rather than wood that has more of a 'doonk' sound. Then I saw they had a speaker implemented..
Green schmean, I just think it'd be a good speaker enclosure... and for a DIY'er, worth the extra tool costs.. For a mass-producing manufacturer, maybe not.
-C