Often compared to the condensed version, Evaporated Milk is anything but.  While only having a portion of the water removed, and being stored in a can, it also must be processed more to prevent bacterial growth in the storage process.  Depending on what brand you choose, you can store it up to a couple of years.  The best feature is that when combined with equal parts of water, the result is the equivalent of fresh milk, which can really save you when you are in a pinch.  Yet it offers a unique taste that make it a perfect ingredient in cooking as well.