Make Your .NET Data More Useful with Treemap Visualization

Someday someone will port this to Silverlight...  

The Microsoft Treemap control requires your XML to be formatted in a particular way in order to successfully parse and render the data. An example of this XML is seen in the following code:

<Nodes EmptySizeMetric="0">
 <Node Text="Americas" SizeMetric="50" ColorMetric="-40.1" ToolTip="Americas">
  <Nodes EmptySizeMetric="0">
   <Node Text="USA" SizeMetric="100" ColorMetric="0" ToolTip="USA">
    <Nodes EmptySizeMetric="0">
     <Node Text="Texas" SizeMetric="20" ColorMetric="40" ToolTip="Texas">
      <Nodes EmptySizeMetric="0"/>
     </Node>
     <Node Text="California" SizeMetric="60" ColorMetric="0" ToolTip="California">
      <Nodes EmptySizeMetric="0"/>
     </Node>
    </Nodes>
   </Node>
   <Node Text="Canada" SizeMetric="20" ColorMetric="200" ToolTip="Canada">
    <Nodes EmptySizeMetric="0"/>
   </Node>
  </Nodes>
 </Node>
 <Node Text="Europe" SizeMetric="25" ColorMetric="100" ToolTip="Europe">
  <Nodes EmptySizeMetric="0"/>
 </Node>
</Nodes>

Source: Make Your .NET Data More Useful with Treemap Visualization