This extension This extension (fixed link) for Firefox has been in development for a while, but now it has reached perfection. It puts a small icon in the bottom right corner of your browser window with the number of new messages in you Gmail account. When new messages come in, you get a small notification window, and when you click on the icon your Gmail account opens in a new tab, new window, whatever you like. I used to need to leave a Gmail window open all the time, but no longer! If you use Gmail and Firefox, this is one of those "how did I get by before I had this" extensions.