In this article Peter Bromberg shows
how Duplex polling can use the "push" model to send subscribed realtime stock price updates to connected clients.
I was asked to prototype something with the Duplex Polling feature of Silverlight 3 for some new Silverlight applications we're working on for eggheadcafe.com. So, like any good developer, the first thing I did was set out not to have to reinvent the wheel. I found several good examples of duplex on the web, but the one that best suited my needs was the "Duplex End to End Sample". This is a well-written simple chat service that also sends out a fake random stock price update using the "Push to all clients" model.