http://drupal.org/project/vertical_tabs

dmitrig01 released a newer iteration of the VErtical Node forms mock up with the addition of summaries in the tab.

Joakim Staie/Ximo gets kudos for getting the first stable version which was used in the usability testing by Interaction Design and Information Architecture program. The video of the usabiility test using vertically tabbed node forms can be seen on: http://buytaert.net/usability-usability-and-usability

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 >>> Read More

While looking at bebo.com for ideas for social network features, I noticed they have on the front page they have a carousel style of vertical tab selection for their latest videos. I probably wouldn't have noticed the feature if I hadn't proposed vertical tabs for Node Forms in Drupal 7. The Carousel style of selection could be useful for selecting video galleries and photo albums and I think makes for a great user experience. To me, I find bebo has a much nicer user experience even though facebook has a lot more on offer.