Firefox's Most Underutilized Feature

Firefox is one of those programs that whenever there is something that you wish it could do, all you have to do is look a little harder because it probably does it. If your version doesn't do that particular thing then there probably is an extension that takes care or it. Or someone coded a fix in Greasemonkey. Anyway, the point is that the browser is an incredible platform and if you feel something needs work then there is usually someone who got there first. There are enough extensions and articles about extensions that most Firefox users have had some sort of pleasant experience like this.