I am currently learning a ton about MVVM and testing on Windows Phone.  If you are just starting to build an application, I highly recommend checking out Jeff Wilcox’s post about his Silverlight Unit Test Framework. (jeffwilcox.com)

You’ve certainly used a ListBox control before, but you’ve likely been pining for a ListBox that allows drag-and-drop re-ordering.  Jason Ginchereau has created one, and made it available.  Check it out on his blog. )(Jason Ginchereau’s blog)