I have several Gmail accounts for various reasons, now checking multiple account emails through a browser can be quite a pain since you have to sign in and sign out to access those accounts. However, Google is testing a new feature which will allow users to sign-in to multiple accounts at once.

The new Multiple account sign in works with Gmail, Google Calendar, Google Reader, Google Docs, Google Sites and Google Code, however, Google may add support for different sites too.

Multiple Sign in will allow you to open different Google accounts in different tabs and you might not have to open another browser for it. This is definitely a great feature and I am eagerly awaiting it’s release since it will definitely increase my productivity. What about you? If you cannot wait for the feature to come out, you can try out the Gmail Notifier for Windows 7 which notifies you whenever a new mail arrives in your Gmail account and supports multiple accounts.

(Source)