We keep on hearing requests for more details on how to create your own data graphics.  Bill Morein's post gave you the basics, and now Mark Nelson on the Visio PM team has written a much more detailed article on this topic (and data graphics in general) and posted it up on MSDN:  http://msdn2.microsoft.com/en-us/library/aa468596.aspx . This should give you everything you need to roll your own text, icon set or data bar callouts.  Looking forward to seeing some of the new ones that folks come up with!