Is there any Firefox or Chrome add-on to highlight search terms (and jump to them ?)

I had this frustration too, and found that Googlebar Lite is a near-perfect replacement for the now-defunct Google toolbar. It allows most of the functionality of the original Google toolbar, but it still works with current versions of Firefox. The "marker" button for highlighting the search terms and the ability to click a search term in the bar to go right to it in the page both function perfectly in this add-on.