Sergio,
Here are some recipes from an article by JulieAnne White here at Slowtwitch.com:
http://www.slowtwitch.com/...l&text=smoothies Here are some more I found:
http://www.velocoach.com/recipes.htm#shake1 It's fun to experiment with shake recipes. You can just start with 8-12oz. of the liquid of your choice, water,fruit juice, non-fat milk, soy milk,vanilla or plain rice milk. Then add either a scoop of whey or soy based protein powder and some fruit. There are also many commercially available shake mixes that can be used as a starting point, "Spiru-tein" is an example. Adding frozen fruit or ice cubes to your blender gives a nice texture. Try frozen banana slices or other fruit, a dash of cocoa powder, some Ovaltine or a dab of almond butter or honey for variety. Try lots of different things you'll discover something you like.
You might want to keep track of the nutritional content that you add, because it's easy to pack these shakes with lots of calories.
Richard