I agree completely with your idea. To expand on it; i think you should also be able to hold different liquids in it, It could be filled with achohol (for a low level painkiller), coffee (For low level night-vision or being more attentive/alert) or it could be used to hold a VERY small amount of fuel, enough to give a motorbike or ATV enough to get to another town.One other thought, i think it would be really cool to be able to poison or infect another players canteen so that he/she can be killed stealth-fully. I strongly agree with your idea sir, you have my beans!