Mirror two data frames

Is it possible to link two data frames so that they mirror each other? I know I can set the extent of one data frame to that of another data frame, but then you can only pan/zoom in the parent frame. Basically just want the two data frames to mirror one another.

I would like the flexibility to pan and zoom in which ever data frame is active, not just the "parent" data frame. This is different from setting the extent of one data frame to match that of another, where only the parent data frame has the ability to pan and zoom. I am using ArcMap 10.1.

I have made this suggestion to ArcGIS Idea: Mirror Data Frames - ArcGIS Idea