The Isolated Storage Explorer Tool is new with the Mango SDK (7.1). In this video I am talking about general capabilities of the application and why you should use it if Isolated Storage is a component part of your application.
Video lost since old blog.
The third-party tool I briefly mentioned is located on CodePlex.
PS: I really did move to YouTube from Vimeo for the Windows Phone 7 Guide project, because the second had restrictions on the volume of HD videos I could upload per month, and 500MB is not enough.