At first glance I thought this was just a gimmick. Why not use your blender? But there are too many 
good reviews of this thing to be wrong. The Yonana machine turns frozen fruit into a healthy soft-serve treat. You put the ingredients in and get what comes out in a similar consistency of frozen yogurt or soft-serve ice cream. The chute can accept sliced mango, berries, sliced cantaloupe, etc, and don't forget to add the banana.
Heck for only $59.95 it is worth a shot.