Debugging Rails App in Realtime with the breakpointer

1) include the line: breakpoint "some description goes here" where you want the program execution to stop.
2) From the rails app root directory run: script/breakpointer
3) Fire the browser and let the app hit the breakpoint, you will be taken to the >> prompt where you can examine variables.

This helped me to customize the Attachment_fu plugin so that image upload is optional.