The new Window 7 Pin feature is automatic. The user doesn't have to do anything (other than chose Pin/Unpin). If you have (say) an Office icon in the task bar then hovering over that produces a pop-up tile that shows recent files opened by Office as well as a view of the current file open. If you want to Pin that (or one of the other files) to the Tile then you chose that option and in future simply click on it to open the Application and File. It's very very useful if you use many different files in the same Application.