I use extracts in my shakes everytime I do a vanilla Protein, with lit vanilla soy along with a few drops of coconut extract and it tastes like Cake batter ...yum
You can also use a plain protein, and use a couple drops of pineapple and a couple drops of coconut extract and make pina colada ...
Also to chocolate protein, you can add a few drops of mint or strawberry..and its amazzzzin.
Also I use PB2 with the cocoa, and put about a tablespoon in plain protein and its really good that way too