Features:
Pinch to Zoom Support
Drag (swipe) support.
Replacement events for the mouse move fires only when a single finger detected.
Multiple events based on gestures.
Performance optimized, memory footprint is minimal.
To use this SDK you will need Visual Studio Professional or better. start a new Smart Device Project, and add the SDK to your references.
The SDK is consists of only one object, which is DualTouchSDK. We will need one instance of this class for every control that supports pinch to zoom or drag in your application.
There are several methods, properties and events that can be utilized in order to achieve multitouch effect. i have done my best to make this as easy as possible, my code is now complex but it is necessary to achieve easy implementation.

More info and download with documentation is available here

http://www.windowsphoneme.com/?p=386