Sample Data has been available to us from Expression Blend 3, but now with Blend 4, Silverlight 4 and Expression Blend 4 SDK there is new control – PathListBox enabling you to create list box looking however you want them to look – not just rectangular. This allows you to create nice radial, spiral and many other types of layout.

Read the complete post at http://www.uxpassion.com/2010/06/silverlight-4-tutorial-how-to-pathlistbox-sample-data-blend-4/