SharePoint 2010 renders fields on a list view is with **XSLT style sheets**, so there is no method to override. If you want a your own way of rendering on list views, you need to create a custom XSLT style sheet named `fldtypes_*.xsl` and deployed it to `(14 hive)\TEMPLATE\LAYOUTS\XSL`.

 - [How to: Create a Custom Field Type][1] (paragraph *3. (Optional) Create a Custom XSLT Style Sheet*)
 - [How to: Customize the Rendering of a Field on a List View][2]


  [1]: http://msdn.microsoft.com/en-us/library/bb862248.aspx
  [2]: http://msdn.microsoft.com/en-us/library/ff606773.aspx