Maurice de Beijer has made a good Silverlight tutorial in which he explains how to change the MouseOver effect on a Silverlight ListBox.
One thing I occasionally have to do is change the way a ListBox item behaves. For example the blue highlight effect when the mouse hovers over it. Changing the blue mouse over effect to something else, say the item growing slightly isn’t very hard using Blend. However I find the steps a little awkward so this post should help me remember them and I hope it helps someone else as well.