First, the Next and Previous buttons are backwards. See this page for a visual. But let's ignore that for a bit.
Second, Firefox always scrolls long pages such that the search string, if it appears on the page, is positioned at the very bottom on the page. Aren't there some better algorithms than that? It's often the case that the first occurrence of a word is the first of many occurrences, but all the subsequent hits are hidden below the visible window region. At a minimum, FF should scroll so the string is in the middle of the page.
Third, I'd like Firefox to highlight all occurrences of the word. Maybe my usage pattern is very different from most people, but I'd like to see all occurrences highlighted, and the "Highlight all" button removed. Why would you not want to see all the results? Search engines don't return one result and wait for you to say "Next". Further, sometimes the string is hard to see on web sites with strange color choices. I'd like to see someone come up with a way to make them more visible (without blinking, of course).
Fourth, I'd like for the the text I'm searching for to remain highlighted across page transitions. If I'm looking for a term on a page, and then click on a link to another page on that site, I'm frequently looking for the same term on that page also. So I hit "Highlight all" again, click to another page, click "Highlight all", and so on.
The Google toolbar does some of what I want, but it seems to only do it when I've sent the query string to Google. What about pages on my home or work networks?
I spend time each day trying to find the right stuff on a page. I'd like to see some real innovation for Firefox 4!
Is there a plug-in that I should be using?