I've needed a decent size smoothie to take on the bus with me in the morning, but not too big. I usually get 2 huge mug-size fulls out of it and it keeps me full and happy (even if i'm standing on the bus with 800 lbs of books on my back haha).
1/2 cup blackberries
1/2 cup water (more or less- depending on how thick you want it)
you know the drill. put fruit in blender and slurp away.
ps- this is really delicious so i urge you to try it!