What to do with old coffee beans?
Coffee can be used for a variety of things BESIDES drinking straight.  Off the top of my head, you can use less-than-perfect beans for:


Chocolate mousse and cakes: brew into coffee, and add to the chocolate mix for a richer flavor
Ice cream and sorbets.  Coffee ice cream is awesome, and the cream will mask defects
Chocolate-covered coffee beans.  These make a great pick-me up snack for mornings, sweet and caffeinated. 
Coffee-flavored simple syrup, for baking and cocktails.  Use equal weights coffee and simple syrup. 
Compost.  Grounds compost very well, especially if used


In a pinch, stale beans also make great projectiles.  Got squirrels on your bird feeder?  Coffee bean slingshot!