Take an industrial 3.5" SBC board (with Socket370). For the project I selected a 1.5 litre Ballantine's bottle for case. That was the proper size and shape for the task at hand. Add an Intel P3 733EB processor, a 256MB notebook RAM, a 40GB notebook HDD and finaly a 60W mini-ITX PSU. The RAM module is placed at the back side of the mobo, and a compact flash card slot is also situated there. After OS installation and stuffing components into the bottle about half an hour of running -it was a bit warm. Glued in an old VGA card cooler into the bottle neck to help the air flow out, and drilled 6 additional holes at the side panel so now the fresh air can flow, these little tweaks improved the cooling and the temperature, resulting in a silent computer that blends in any empty bottle collection.