gleeBox for Firefox
Do your mousing muscles ache after browsing the Web? The GleeBox experimental Firefox add-on and Chrome extension let you perform many tasks by using your keyboard rather than the mouse--including some tasks that require multi-step actions.
Install the GleeBox add-on into Firefox and type "g," and you'll see a big transparent grey box in the middle of your screen. Then type in a letter or series of letters, and you'll be sent to the first link on the page that contains that letter or letters. The links will also be highlighted in yellow. When you are at any link, press Enter to open it. To go to the next link, press the Tab key.
That's just the start of what this clever script can do. Want to share your current page using Facebook? Type "fbshare $. How about searching videos of Sting on YouTube? Type :tube sting. You can also do much more with gleeBox, such as shortening the URL of the current page using the bit.ly service so you can share it with others.
If you're happy with the way you browse the Web, there's no need to use GleeBox for Firefox. But if you want to minimize your mousing, it's well worth a try.
Note: This is the Firefox version. If you would prefer to use Google Chrome, download the Chrome extension instead.