While it's possible to drive Mozilla or Firefox entirely using the keyboard, it's really not very pleasant: you have to use Tab to move between links, it's not very obvious which link is highlighted, and moving up or down by pages don't update the selected link (so if you page down then hit Tab to move to the next link, you end up on your original page).
The problem of effective keyboard navigation in a browser has been solved for a long time in Lynx, and the same model's been adopted by other programs like Links and pinfo. I'd like a Mozilla/Firefox extension which gave me Lynx-style keyboard navigation: up and down move between links, scrolling around in the document also affects the selected link, and the selected link is highlighted in a very visible way.