Have you ever thought of using keyboard for navigation in websites (other than login page)? It is very difficult with websites, because they may contain hundreds of links, and we may have to press tabs more than hundred times. So, everyone uses mouse.
Opera supports spatial navigation. If you press Shift + Arrow, the control would be moved to that direction. You can use the arrow keys with shift to goto the link you want. This is much faster and easier way than pressing tab hundred times.
For more information read the article by Jeff Atwood.