Through a series of links I chanced upon Casper Electronics and Peter Edwards, a circuit bender and electronic musician/artist who has both an enviable amount of talent and equipment. The site offers an incredible array of his hacked toys and gizmos, tutorials, and then there's this:
Edwards offers this as a kit for $200.00, or you can buy just the circuit board, or even a pre-built unit.
Here is my own feeble attempt at a little noise box:
I am eager to get back to it once it warms up and I can go out to the workshop in the freezing cold laundry room...