WCF Duplex Service Links:
1: How to: Build a Duplex Service for a Silverlight Client
2: Silverlight and WCF Feature Comparison
3: Building and Accessing Duplex Services
4: WS Dual Http
5: How can I send a notification message from server to all clients in WCF (broadcast you can say)?
6: WCF Callbacks; a beginners guide
7: Default NetTcpBinding
8: How to set up a WCF client using wsDualHttpBinding in code?
9: Pushing Data to a Silverlight Client with a WCF Duplex Service - Part I
10: Pushing Data to a Silverlight Client with a WCF Duplex Service Part II
11: Duplex Communication with WCF in Silverlight 4
The following seems not for Silverlight client ?
9: How to: Create a Duplex Contract