My mouse died today.
When I wanted to add a comment with just the keyboard, I found that it was just not possible.
Allow for me a way to be able to add comments without having to make use of the mouse.
Windows has MouseKeys and I'm assuming OSX and Linux have something similar, so it is possible given the right configuration of your system.
I would imagine that the kind of user who never used a mouse - rather than just on the odd days it was broken - would be familiar with such tools.
I hadn't noticed the missing tab behaviour; but this works with gleeBox on chrome (yes I know the question was opera):
Note that since "add c" is in the title, you'd have to press [tab] to get to the right link.
But gleeBox is great; I have it set to apply a jQuery selector by default (