I'm looking for a substitute to milk in the coffee... something that will have the same effect on the coffee (tone down the bitterness of a coffee cup) put that wont turn bad after two weeks.  Here's the situation... I do like to take a good coffee when I'm a little sleepy on the job... that happens, well, maybe once a week.  But if I buy a 1L carton of milk, it will have the time to turn bad before I'm at the halfway point.   So is there a product that I could use to substitute the milk in my coffee that wont turn bad? 
If you take your coffee sweet, ice cream works wonders, and it lasts in the freezer.  Chocolate is my favorite.  I recommend melting it before adding the coffee.  This makes sense because ice cream is mostly milk and cream, with some flavorings--usually of higher quality than are in artificial coffee creamers.    I should add the trick I used in the dorms some years ago, when I had no refrigerator (and an aunt to buy it):  Bailey's Irish Cream.  Of course, the effect is somewhat different :-) 