Firefox: When you view your browsing history, you get a chronological list of sites you visited, from oldest to newest. What you don't see though are the sites that linked you to the following ones, or the search results that gave you the next three sites you visited. FromWhereToWhere for Firefox fixes that.
Once you've installed FromWhereToWhere, you can click the extension in your Tools menu to bring up an ordered and threaded view of your browsing history. The list is indented to show you how you got from search results, for example, to the site you're currently viewing. The threaded view also shows you at a glance which sites you clicked from search results and which sites you visited later by keeping sites opened at the same time on the same level and indenting other sites farther to the right.
Best of all, unlike Firefox's default behaviour, you can open a site in your history without forcing it to the top of your history list, or by changing its position in the thread. Just double-click or right-click and open it in a new tab to go back to it without losing your place.