Gleebox: it's like command-line surfing in Firefox or Chrome, but more awesome
I won't get into the details, but a big part of avoiding RSI (repetitive strain injury) from computer use is not moving your hand to the mouse quite so often. And that's what Gleebox does: it actually puts a 'console command line' right there in your Firefox or Chrome window.
Instead of moving your hand to click on a link, hit 'g' and start typing. Gleebox's default behavior is to cycle through links which match your search phrase: type 'Google' and then tab through every link with 'Google' in it. Follow a link by simply hitting enter: voilà!
But it does so much more too -- it's a bit scary, actually. Brace yourself and have a look at some of the commands in the user manual. Amongst others, you can share a page directly to Twitter or Facebook. Search Google or Wikipedia without having to pop open a new tab -- do it directly from the Gleebox. The neatest thing is probably the screen-scraping commands though: type '?h' into Gleebox and tab through every 'header' element in the page, perfect for reading news quickly. Likewise, '?img' cycles through the images on a page - neat!
If that's not enough for you, there's full yubnub and jquery support too. Want to cycle through every input box? No problem. Every piece of italic or bold text? Sure! Convert the page you're on into a PDF? Alright, Gleebox, what can't you do? It's free and open-source too...
If you're the kind of person that simply hates reaching for the mouse, Gleebox is certainly for you. You're doing your hands an injustice by not using it -- and as a computer user, that's just down-right stupid.
Try Gleebox Now (Firefox users will need Greasemonkey.) -- or watch the introductory screencast, if you still need more convincing.