scroll-all

This mode allows multiple buffers to be 'locked' so that scrolling
   up or down lines in any buffer causes all the buffers to mirror
   the scrolling.  It hooks into the post-command-hook to check for
   potential scrolling commands and if we're locked, mirrors them in all
   windows.  This allows us to grab line-at-a-time scrolling as well as
   screen-at-a-time scrolling, and doesn't remap any of the keyboard
   commands to do it.

You can enable and disable this mode with the 'scroll-all-mode' command.

Suggestions/ideas from:
   Rick Macdonald <rickm@vsl.com>
   Anders Lindgren