Have you tried about:robots in Firefox 3 ? neat huh.. just copy paste it in the address bar I blogged about a few Firefox tricks and features here : http://www.saijogeorge.com/2008/10/04/some-hidden-less-famous-features-of-firefox-3.html
Have you ever thinked that Opera is much better? No, really. Look at ACID tests. Look at following feature list: Tab Mix Plus / Internal tab manager - since 8.0, year earlier than FF Tab switching by keyboard - same Custom CSS styles - since 2003, including high-contrast mode instead of default "I rape your eyes with 120dpi Tango-colored interface" Other extensions? Errrm... DOM explorer, error console and color picker are quite useful when you're learning something - yet not after! Mobile version? There's no mobile firefox, no mobile xulrunner and so on. But it [FF] has about:* namespace to drive all the funky Rasta users to use this /skipped/. That's a major bonus.