do some searching in the Ask Sarah section. She has listed milkshakes and smoothie recipies on several occassions. Feb 13/2000 I got a few using soy and on June 8/97 I printed off a list of 19 milkshakes and variations.

I know you want fruit smoothies but these may give you some ideas to get started as they are not all icecream based traditional "milkshakes".

Experiment and have fun!
Emilee