Seperate into bags of how much you'll use in a week.
Put all except one into freezer.
Use that one.
Use another one after that.
Continue, etc.
(rnuk http://flickr.com/rnuk, Tue 12 May 2009, 16:18, archived)

grinding them from frozen actually seems to work better
it makes the beans more willing to jump into the mashy jaws of tasty death
( spacefish bong!, Tue 12 May 2009, 16:24, archived)