A familiar problem: You have a quantity of liquid, and no place to put it. Try putting it in a backpack, it seems to disappear (and, strangely, the backpack appears to get wet at the same time). Store it on your computer, and as often as not, sparks fly out of it and it stops working. Hold it in your hand? Not for long. Liquid! So annoying!
Unless you have one of these liquid containers. They'll hold your liquid safely and securely, with an open top so you can keep an eye on it. Comes with a convenient "carry handle" so you can pick the container up and carry it around with you, thereby moving the liquid from place to place. Available in black (to avoid glare in bright sunlight) or bright green in case you'd like your liquid to be visible from space.
Conveniently doubles as a coffee cup.