What would you do if you could get hold of liquid nitrogen for $1.50 per litre? Overclock your Arduino from 20MHz to 65.3MHz at -196°C? We though so...
Michail managed to find the super-cheap liquid nitrogen from a company selling to the public in Moscow, and decided to overclock his Arduino. Unfortunately, Arduinos are not really set up for overclocking as readily as desktop processors are - there are no stability tests and the like. However Michail has managed to overcome the odds, and clock the board at over 3x it's original spec.
He found out loads of new information during the project, with the most notable being that LEDs change colour when subjected to such extremely cold temperatures.
You can read more about his adventure here.