The following is a direct quote (with actual images instead of image links) from a post I made on:
http://groups.drupal.org/node/10105#comment-34593

In acidfree galleries, having the vertical tabs horizontally laid out above the node content wasn't exactly the best placement.

I re did a theme and inserted vertical tabs to the left of the node content (floating the tabs to the left and the node content to the right with complementary widths.)

The image link displays how vertical tabs can be used to navigate between local tasks (I hope thats what local tasks are) of view and list options in acidfree galleries:

Vertically Tabbed Node Options

As a side effect, I noticed that the user log in form benefited from the the above changes to the theme:

Vertically Tabbed Log In Options

While the use of vertical tabs for local tasks is best left to visual designers and information architects to decide on for their websites, having a default theme setup to use vertical tab placements, such as in the above linked images, could prove to be useful if such placements were supported right out of the box.