Have more than one Google account and want to sign in to all your accounts in same browser simultaneously using multiple tabs? If this was your wish for a long time, then the Google's god has fulfilled it!! Until now, you could do it only using different browsers as Google stores your log in information using browser specific cookies on your system.
How to sign in to multiple Google accounts using same browser?
When you go to the
Google accounts page, you might see a new option: "multiple sign-in". If you don't see the new feature, it will probably be enabled soon.
After clicking on the "change" link, Google informs that this is an advanced feature and that it will only work for Gmail, Google Calendar, Google Sites, Google Reader, Google Voice, App Engine and Google Code.
When multiple sign-in is enabled, a drop-down is displayed next to your email address at the top of the page, so you can quickly switch to a new account.
If you use multiple sign-in, the first account you sign in to will be your default account. If you visit other Google products that don't support multiple accounts after you've signed in, you will automatically sign in to your default account for that product. If you sign out of any Google product while signed in to any account, you will be signed out of all your Google Accounts at once.
using this feature, you can read your messages from two or more Gmail accounts by opening Gmail in multiple tabs.
Via:
Google OS