Smooth in the City is a cute little shop in Montmartre that makes smoothies that actually taste like fresh fruit. That's because they contain nothing but fresh fruit. There's no added sugar or mystery "powder" that many smoothie shops in the US sneak into the blender.
The owner was a sweet as the decor, and I'd highly recommend stopping by the next time you're traipsing through tourist ground central on Rue Abbesses.
11 Rue des Abbesses
PS. How many of you want a pink chalkboard now?