Up until a version or two ago, I would just keep hitting Command+W as I finished reading tabs in Firefox, and when I closed the last one, the window would go away. I’m not sure why this doesn’t work anymore, but I just found out that Command+Shift+W will close the current window. It’s not as fluid as it used to be, but it makes me a lot happier than having to use the mouse or just using Command+H to hide the window until I need Firefox again. I figured I’d share, because I can’t be the only one who hadn’t figured this out.