The downing of a drink as quickly as possible.
The ultimate shotgun requires a bottle of (preferably non-fizzy) alcoholic beverage and two straws.
1. attach the straws together end to end and ensure no side-leaks to air.
2. insert straw into bottle ensuring tip is as near to the bottom as possible.
3. form a food seal around the mout of the bottle and the straw with your lips.
4. tip the bottle up so that it lies vertically (that's
straight up and down for all
the Americans out there).
5. At the same time open your gullet and have someone else blow on the other end of the straw as hard as they can.
The contents of the bottle should disappear in under a second - good shit.
6. To ensure it has gone down and stays down you must now shout "BOOOOOM!" at the top of your voice. If you spew you have to forfeit.