If there's an active region, d and u operate on all buffers in the
region.

Some variables that can be configured:
- org-buffers-buffer-properties
- org-buffers-excluded-modes
- org-buffers-excluded-buffers
- org-buffers-follow-link-method
- org-buffers-mode-hook
- org-buffers-buffer-name

Some possible extensions:
- Browse recent files using recentf
- Allow several buffers to be marked for side-by-side display
- Maintain folding configuration across buffer updates
- Make faster

As always, any feedback, suggestions and patches will be very welcome!

Dan

p.s. The column-view mode works for following links, but does need
further attention.