Should you be an avid Pinterest user, you'll want to check out Pinsation for Windows Phone. Using official APIs, Pinsation provides a seamless experience with facebook connectivity and all the features you'd expect - upload pins, re-pin, like pins, create boards, delete pins, comment on pins, and more.
If you haven't heard of Pinterest before, it's a startup that allows users to find and "pin" useful content that's discovered around the web. Think of an e-pinboard and you'll understand the concept.
Pinsation also enables the user to pin categories, searches and favourite boards right to the home screen for more convenient access. You can download Pinsation from the Marketplace for free.