This is the first of many mini-tutorials on the Silverlight 4 features that Jesse Liberty intends to write.
An enhancement has been made that allows you to add animation when items are added ,or removed from, the list box. Silverlight 4 adds a new StateGroup to the ListBoxItem class. To demonstrate this, I’ve created a wicked simple demo: the user types into the text box, clicks the add button and the text “floats” up into the list.