Windows Phone Power Tools
Necessity may be the mother of invention, but it's also often the mother of Open Source tools which are not really reinventing the wheel, but perhaps make our lives just that little bit easier (or more functional). A common pain point, especially as more and more developers move their apps to Mango is testing update scenarios and exploring the IsolatedStorage of a developer app, both extremely handy debugging tools to have that either don't exist (updating developer apps is not really possible) or are very basic (the IsolatedStorage Explorer tool that ships with the SDK).
To this end, I've published a little Open Source app that I'm dubbing the "Windows Phone Power Tools" that allow you to do just that - update developer xaps, visually explore the IsolatedStorage structure of your apps and a bunch of other small, but handy, features.
You can check it out on codeplex: http://wptools.codeplex.com