Here are a couple of great summer smoothie recipes.

Cantaloupe-Coconut Smoothie (contributed by Elizabeth Bushman)
1/2 cup low fat milk
1 cup nonfat frozen vanilla yogurt
2 tbs cream of coconut
3 cups chopped cantaloupe
1/2 cup chopped fresh pineapple
1-1/2 cups crushed ice cubes. 

Kid Friendly Spinach Smoothie

2 c blueberries

1 vanilla yogurt

fresh pineapple chunks

ice cubes

2 c fresh spinach (yeah spinach)

Kids are lovin' em!

Smoothie Tips*
Freeze the yogurt, bananas, and berries, etc.  I have never frozen cantaloupe.
If your fruit is frozen then you can skip the ice.
I don't really chop a lot or crush the ice, as my blender does this well.
Freeze any leftovers and make Popsicles.  I use the 5 oz wax bathroom cups and spoons or Popsicle sticks.