Visio 2007 introduced Data Graphics but, in my opinion, didn’t provide any automatic legends for the icons and colour by value options. That is why I wrote DataLegends (see http://www.bvisual.net/Products/DataLegends.aspx ) as an add-in for Visio 2007 several years ago. This oversight was remedied in Visio 2010 when Microsoft introduced their own legends (which were not totally dissimilar to my own), and also added a method (Page.DropLegend) for programmers to automate this task.