User-Data
Windows Phone 7.1

The Windows Phone 7.1 user-data helper assembly is used to retrieve user-data from Windows Phone. The user-data is stored in a view-model class, making it usable in XAML controls.
This user-data helper currently supports the contacts section within Windows Phone's user-data model.
This user-data helper also support populating sample data, which is useful when using the emulator mode. However, the sample-data only supports populating the view-model items, since Window Phone's contact classes are read-only by design.
Note: This user-data helper requires the storage helper in order to store XML data.