Here's one for hot-key lovers - Mouseless Browsing makes your mouse redundant when browsing the Web.
Once installed in Firefox, you'll see the little icon on the bottom right of the browser. Your Web pages will now have numbers next to every link (this feature can be turned off when not in use). The idea is that you tap in the number, hit Enter and Mouseless Browsing 'clicks' the link. Tapping a number while holding Ctrl clicks the link automatically, and while holding Alt it opens the link in a new tab. Back, forward, reload and so on are all singe key taps.
The most obvious criticism of Mouseless Browsing is that web pages don't look very nice with hundreds of numbers plastered all over them. My second bugbear is that the instructions aren't very clear, making learning even the basic commands a bind. This is strictly for the hardcore keyboard lovers among us.
If you find the mouse an intuitive way to navigate web pages, Mouseless Browsing is unlikely to change your mind. I found I still needed the mouse sometimes as some pages like Gmail are awkward to use. Not all of the links were given number IDs, most irritatingly the 'compose' and links to mails themselves!
If all you're doing is reading and watching things on Web pages, Mouseless Browsing is quite a neat way of navigating without moving much, once all the commands have been learned. It takes some time to get to grips with, however, and it's hard to see how the investment is worth saving fractions of seconds here and there, especially as it also makes the Web uglier.
Mouseless Browsing is an interesting concept, but it's hard to see the advantage of a less-intuitive control system than the trusty mouse.