I was looking for something along these lines, but I really just want the h, j, k, l movement keys. Those combined with the / (search in page) and ' (search links in page) shortcuts would dramatically cut down my use of the mouse when browsing.
i've used keyconfig for that for many years (and is consequently why i get so frustrated at websites that default to focusing some search text box when the main function of the page isn't to search).
it isn't marked as compatible with firefox 3.5 but i've tweaked the xpi file to say so, and it works fine.
