I love this pipe organ project by Matthias Wandel. It's so totally obvious that the builder is a computer programmer. The parts he cares about are beautiful, then then you start looking around a bit and you see the rocks being used to balance things properly and the jury rigged blower motor that uses a variac to provide the right amount of air. And I love how it was obviously done as a bit of a lark, over a week or two. It's just wonderful. The other homemade pipe organ projects that he links to are worth looking at as well, but this one is by far the coolest.

Oh, and check out the rest of his site, it's full of interesting little projects. This is one of my favorite websites, I go back once every few months just to see what new stuff he's done.