I found this article with CAD files to 3d-print a AA battery tray for the MessagePad 2000. I was wondering if anyone had successfully tried this, as I don't have any battery for my Newton and I'd like to be able to use it as a PDA. 3D printing the piece would be much easier than trying to find a real one, and if it works, I don't care too much about the aesthetics (though I'd probably paint it to make it look somewhat believable...)