Always store 2 litre bottles of soda, once opened, on their sides in the fridge. As long as there is enough soda in the bottle to cover the cap, the soda will keep its fizz.
By Jo from Riverside, RI
Instead of throwing away half a can of soda or leaving it to become decarbonized, place a balled up piece of foil in the drinking hole sealing off the majority, if not all, of the can.