about:crashes Shows You Every Submitted Firefox Crash

From the files of the Maybe New To You Dept.: While Firefox 3 should be a bit less crash-prone than its predecessor, it isn’t bulletproof. Type about:crashes into Firefox’s address bar, and you can see a list of your browser crashes, when they happened, and click on them to get details of what happened. Some of the reasons and reports might not be in plain English, but a little copy/paste-to-Google could help diagnose your problems. This will only list the crashes after which you clicked “Submit” on the resulting pop-up, so you might want to think twice before hitting “cancel” after your next sudden failure.