Read original post by Matthias Shapiro at Designer Silverlight
This is a full-featured tutorial, walking through design, structure, UI and photo formatting. If you just want to know how to get from a Windows Phone 7 PhotoResult to posting that photo to Facebook, skip down to “Capture and Format the Photo” and start from there.
This post assumes you’ve gone through the process of setting up the permissions for a Facebook app and getting your user to log into Facebook through your app. In short, it assumes you’ve walked through this tutorial.