New Field: Last Modified By

Would like to see a field for last modified by. It would truely help to see who last touched this ticket. Expecially when I have people asking the reporter questions and not assigning themselves the ticket. Maybe that's a work flow thing but a true history of the ticket would include all people who have been assigned or have modified this ticket. But for starters id be happy with a Last Modified By.

Thanks for all the great tools guys!