If you like the idea of using the mouse less while browsing, then you'll love Vimium. Lifehacker has a post introducing this Vim-inspired Chrome extension. Chromium users get the same love, too.
Best of all, it's open source.
There's even an introductory video to get you started. I've included it below for the lazy.
Being inspired by Vim means it uses lots of keyboard commands. But don't worry, you'll be typing mostly one or two character commands. Maybe three.
I've only just discovered this myself, so I'm still learning the ropes. But things are looking more interesting already.