RIAs mean passing data around and XML is one of the big flavors for doing this.

 

The XML editing tools in Visual Studio 2005 and 2008 are really good, and are included in all of the VS SKUs (Express, Standard, and Pro).

 

Here is some good information on using them.

 

http://msdn2.microsoft.com/en-us/library/aa302298.aspx

http://www.lovettsoftware.com/blogs/blog.aspx?id=57

http://blogs.msdn.com/kaevans/archive/2006/02/20/535578.aspx