Multiple Sign in feature from Google allows you to simultaneously sign into multiple google accounts using the same browser to access below Google Products without any interruption.
- Calendar
- Code
- GMail
- Reader
- Sites
When you enable this feature, the most significant change is that you’ll see a new drop-down next to your email address in Gmail and other supported Google products. Click on the drop-down and you can sign in to a new Google Account without signing out from the previous account.
Settings to Enable Multi Sign in Option
Click Settings in top right corner -> Click Accounts and Import tab -> Click Change Account Settings link (Google Account Settings) -> Edit to Enable Multi Sign-in option in your account
