I just tried to figure out, how to pass initial parameters to a Silverlight App, that runs out of browser. We dont have a Webpage to pass InitParams and we cannot access Web.Config entries.
So i came up with the idea, to use Isolated Storage for this task. Before installing an App Out-Of-Browser we need to access the Webpage. In this case, we can read the initial paramters from Web.Config or from Silverlight-Tag, and store them to Isolated Storage.
Now we need a code-block to check, if app runs OOB (Application.Current.IsOutOfBrowser) and in this case, we read the paramters from Isolated Storage instead. So the OOB-App is configured the same way as the Web-App.
This was just one Idea, that worked. Any other suggestions are very welcome.