Reversing the French press
Hammacher Schlemmer is offering a new product called the "Acid Reduction French Coffee Press." Like a traditional press, it steeps coffee in hot water and then filters out the grounds. This one simply reverses where the grounds go, pulling them to the top instead of pushing them to the bottom. This takes them out of the remaining water, preventing the over-extraction that causes too much bitterness and acidity.
It's a neat idea and reasonably priced around $30. But I'll stick with my own solution: using a mug big enough to hold all the coffee in the first place.