If you have multiple Gmail accounts and use Firefox, you don’t have to be opening and closing the accounts to see your mails, for it you can install the extension IE Tab, then open a tab with FF and log there; and then do the same thing, but with IE’s tab. You can see the result in this image.
Even when the trick does not turn out to be so convincing, it’s effective and the tip not only serves for Gmail, but in general for any web service. Once again, Firefox does easier to surf in the Internet.
Via: LifeHacker