Multiple sign in feature of Google

Google recently rolled out with multiple sign in feature. It means you can login to multiple Google (including Gmail) accounts in the same browser.
To start with the service, go to Google.com and login with your Google credentials. Now click on Settings –> Google account settings.

On account settings page, under Multiple sign-in section, click on the “Edit” link.

A new page will appear along with the notification in yellow color. This facility is currently available on Gmail, Google Calendar, Google Sites, Google Reader and Google Code.
Click on the On option and check all the boxes under it (obviously read them carefully before checking). After checking, click on the “Save changes” button.

Now login to my Gmail account. On the top right, a drop-down appears next to my email address as shown below .
Click on the drop down and then click on “Sign in to another account”. A new tab will open, sign in with another Gmail account.