Exchanging Data between 2 XAP files that are in separate browser windows

What's the best way to exchange Data between 2 XAP files that are in separate browser windows or maybe a browser window开发者_运维技巧 and a popup? each html/window with it's own .xap file

Take look at the LocalMessageReceiver and LocalMessageSender classes in the System.Windows.Messaging namespace. For an overview for how this works review Communication Between Local Silverlight-Based Applications.