Michael Bouck sent me mail about a cool "holiday project" add-in he was working on to create a visualizer for XML that you can use in VS2003. It is worth checking out and leaving some feedback for him on the workspace.
Home Page: http://workspaces.gotdotnet.com/xmlviz.
Description Via Project Home
XML Visualizer for Visual Studio .NET 2003 (XMLVIZ) allows you to visualize most XML and XML-backed data sources during runtime a la Whidbey's "debugger visualizers". The difference is you don't have to wait for VS.NET 2005 because XMLVIZ will work with your copy of VS.NET 2003 today!
XMLVIZ is implemented as a VS.NET add-in and, once installed, is activated by highlighting any supported, initialized type instance during a debugging session, right-clicking on the selection to bring-up the context menu, and selecting the "XML Visualizer" menu item. The add-in will then grab the XML out of the selected target instance and display it on a modal dialog along with the schema (if available). For ADO.NET types, the data is also bound to a grid to allow navigation, row-filtering, and row version inspection.
Currently supported types (including derived) are: DataSet, DataTable, DataRow/DataRow/DataRowCollection (attached), DataView, DataRowView/DataRowView (attached), DataViewManager, XPathNavigator, types implementing IXPathNavigable, well-formed XML in strings, or any XML-serializable type.