Recently Michel Perfetti finished up the work on a very useful work item control that lets you visualize the workflow of a work item. This is similar to the graphic view found in the Team System Web Access client but the custom control also has a nice grouping feature which further simplifies the analysis if a work items lifecycle.
The control looks like this:
Download the control and its source code from the Codeplex project TFSWorkflowControl.
If you are interested in how you can implement your own take a look at the Custom Controls for TFS Work Item Tracking project on Codeplex, which has several other controls in it as well as references to documentation on writing custom controls.