I just read a really good analysis of McDonald's "real fruit" smoothies...

Go here and see if you can take the amount of sugar they put into this stuff:
http://spoonfulofsugarfree.wordpress.com/2010/09/09/mcdonalds-real-fruit-smoothies

If the outrageous sugar content turns you off, Alex puts some great Smoothie recipes in her article... cheaper and MUCH less sugar:

Smoothie Ideas:
~I love making smoothies all the time! They are quick and easy to bring. Just throw the ingredients in a blender, and take it to go in a cup! I make mine by putting frozen fruit (or fresh) in the blender, fill it with juice, water, milk substitute, and add other miscellaneous items like spices, extracts, or protein powder

• PiNa Colada: coconut milk, pineapple, banana
• Chocolate-Dipped Strawberry
• Strawberry Mango
• Chocolate Peanut Butter: cocoa powder (or chocolate protein powder), milk, peanut butter, banana
• All the fruit in your pantry smoothie: and add milk and juice!
• Peachy: peaches, papaya, mango, orange juice
• Orange julius: orange juice, ice, milk
• Chai smoothie: banana, milk, cinnamon, chilled chai tea

The possibilities are endless!