The ShopBot is a sort of an electronic saw, a special setup designed to do some computer-aided cutting and carving work on big planks of board. It's quite useful for woodworking or making things like skateboards or surfboards. Odds are that you don't have one, but nevertheless, just such a device was used to make the plank above, a very basic but still elegant iPhone-powered boombox. I think this is a great idea, though it might be a little more hard to do than a lot of DIY projects.
Fortunately, you don't really need a ShopBot to make a boombox similar to this one. You could still follow these instructions, substituting a body created in some other way for the ShopBot board, and use the iPhone dock connector, speaker, and battery pack to serve as the various innards. You can buy plenty of docks that do exactly the same thing, but I like the idea of making one as a DIY project; you can probably build something that matches your own tastes and does practically everything any dock off the shelf will do for you.
Maybe this will spark some ideas out there. If you do think of (and make) something cool, definitely let us know.