I'd really like to see a computer made entirely from transistors, and only transistors. I feel that using ICs hides a lot of it away.<p>Admittedly the thing would be massive, perhaps covering a wall. But it would be a great demonstration of how it _is_ possible to build such a thing using just one key component.<p>Bonus points: make it 32-bit, include an MMU, and boot Linux on it. You may use more than one wall.