Changing the contact dashboard display
Out of curiosity: why would you want to do that?
You can remove it in the css, by adding a little jQuery to a template and then add the template to the Contact Summary, or by changing your specific copy of the Summary template. You can get more information on how to do this on 
http://wiki.civicrm.org/confluence/display/CRMDOC/Customize+Built-in+Screens