Silverlight for Windows Phone 7: ListBox Scroll Performance – Silverlight for Windows Phone Performance team blog – Site Home – MSDN Blogs

Having a basic list scoll is a key scenario for many applications. The
Silverlight Windows Phone 7 list box control makes it easy to bind data and get
the performance benefits of UI container virtualization. However, in order to
get these free performance benefits you need to be careful about how you use it.