If you use less than a full can of beans in a recipe and don't want to waste the rest of the can you have two good options: freezing or refrigeration.
According to culinary site Chow.com, you never want to add foil or wrap to the top of the can and put it back in your fridge. Instead, drain and rinse the beans. Then, if you're going to use them in the next week add them to a plastic storage container with a drizzle of olive oil. For longer-term storage what you want to do is cover the beans with water instead of olive oil and freeze.
The frozen canned beans will last up to a month in you freezer using this method. To use them just allow them to thaw and use as you would normal canned beans.