After some trial and error, mostly error on my part I got these instructions to work.
What I was missing was that when adding the control to the list of controls I had not properly chose 'Field or group (any data type)' when following the instructions outlined in How to add a Contact Selector Control to InfoPath 2007.
See this blog for a more user friendly set of instructions to get the control in your InfoPath form - http://blogs.msdn.com/infopath/archive/2007/02/28/using-the-contact-selector-control.aspx
All is right in the world.