When doing some research on integrating YouTube videos into Adobe AIR applications I came across this presentation. Marco Casario talks about the design patterns and technologies that can be used to aggregate social media networks in AIR. The Adobe AIR Cookbook will be out in November 2008 and will have more information on these topics.
http://casario.blogs.com/mmworld/2008/10/developing-mash.html
I will be posting soon with an example Flex and AIR application that can play YouTube videos (without breaking the terms of service). Many people today are reconstructing the URL to the source FLV which is against the terms of service. Between this presentation and another blog entry about YouTube in Flex applications (On The Other Hand) I should be able to post an example for both.