Schrödinger's Cat is probably one of the most famous thought experiments of all time. Erwin Schrödingercreated the scenario as a means to explain quantum mechanics, but as it turns out, the analogy also works great as a mug. The Unemployed Philosophers Guild is now making matching, heat-sensitive mugs showing identical boxes. Either a living cat or a dead cat will appear when you pour hot liquid in, but you have no way of knowing for sure until you do.
The mugs mirror the scenario that Schrödinger created to point out flaws in the Copenhagen Interpretation. To get super basic, quantum mechanics is concerned with observing things way too small for the human eye to see. In order to observe them, the objects have to be altered in some way, so it's impossible to say what they were doing before being observed. The Copenhagen Interpretation says that an object can exist in all possible configurations until it's observed, when it collapses into just one.
Schrödinger's Cat takes this theory and brings it to a hypothetical, macro-scale. When we think of a cat being simultaneously alive and dead simply because we haven't checked, we see how absurd the idea is.
The analogy comes to life on the two matching mugs, which make the thought experiment a bit more literal. Grab them on ThinkGeek for your own studies, and don't forget that heat sensitive mugs can't go in the microwave or dishwasher.