I was lazy over Thanksgiving freezing my remaining coffees, and when I came back, they tasted like crap. I had put them in the freezer in the half empty plastic storage containers they were in when I was drinking them. So when freezing, use an airtight container and make sure to remove as much air as possible out of packaging.

Most people do this as a matter of course, but it may be useful to know it is required, not optional.

Well before I knew much of anything about coffee I had a bag from a local shop who got their coffee fresh from a local roaster. It was one of the generic white layered-paper bags with the fold over top. I kept it in the fridge. I do not have to describe the taste from them when I pulled them out a few months later, having forgotten they were in there...

But there is worse, as I relate here:
http://home.surewest.net/frcn/Coffee/Coffee59.html

Ughhhhh... I shudder to think about it.

A freezer is one of the worst places to put something that will absorb oders and flavors. The air in there is quite funky so air tight is a must.

I read somewhere that roasted coffee would absorb aromas and flavors more efficiently than baking soda. Roasting coffee around any kind of contaminate (like smoking a cigar by the roaster or roasting in a garage full of wood finish fumes) is a real fast way to ruin your roast. I made the mistake of roasting a batch in the garage with the doors closed after I put some varnish on a bunch of wood one day. Talk about bad tasting coffee, MMMmm solvent flavored espresso. Ice cream is another bad one. Leave the lid off your vanilla ice cream for a couple weeks in the freezer and then try a spoon full.