Turning off your WATER & GAS can be necessary in a long-term, or even short-term emergency. Video and tutorial on how!
WATER:
http://foodstoragemadeeasy.net/2010/05/17/how-to-turn-off-main-water-supply/
Gas:
http://foodstoragemadeeasy.net/2010/03/28/how-to-turn-off-natural-gas/