Hi there - like John and Mylenium mentioned, you'll most likely need to create this effect manually. You can do this by applying stoke gradients to a path, or you can try to create the text out of several segmented objects.
I very roughly duplicated the effect by creating the "ribbon" sectioned up into several objects, as shown below:
Then I just went in an added gradients to each of the individual objects:
Obviously my example was done very quickly, but with some time, you should be able to get an effect close to the example you provided.
Here's a video on using the gradient tool in CS6: http://www.youtube.com/watch?v=Enk4xMVrLtk
And here's a video on adding gradients to strokes: http://www.youtube.com/watch?v=I-6lk5Vxm6U
You may want to try using these two techniques together, as well.
To support Kendall's answer, a Gradient Mesh would also work. It behaves like the gradient tool but allows you to chart points in a grid within an object which can then each be given a unique color. It helps provide a 3-D because it allows you to create complex curves by moving the points around on the grid.
Here is a big list of gradient mesh tutorials to help you out: http://blog.spoongraphics.co.uk/articles/20-tutorials-to-help-master-illustrators-gradient -mesh