Jun 14, 2011 11:31 AM|roopeshreddy|LINK
With ASP.NET web application, you cannot access the Mobile Contacts. If you want develop sync application, then you need to create thick application, which has to installed in the Mobile device.
Web Application has limitation, that those applications cannot access the application or OS services on Mobile device.
NOTE: If you develop application with .NET, it can be installed in Windows Phone only.
Check the following link for developing Windows Phone applications,
Hope it helps u...