Sharing our experience in making code complexity and unit coverage visible in the hallway adjoining our team room and the conversations that happened around it. Not only did it help to focus the team on the high debt areas of the application, but its red (bad) and green (good) coloring combined with its high-foot-traffic location enabled executives in this Fortune 500 insurance company to invest in paying down debt as well.
http://submit2011.agilealliance.org/files/session_pdfs/CodeChristmasTreeAgile2011.pdf