Here is a Step By Step Illustration on How to use Airtel Free Zone Mobile Internet for Accessing Google, Gmail, Google+
Point your phone’s browser to airtel.in/freezone ; click “Enter Free Zone” to access Google’s search engine, billions of Web
sites, Gmail and Google+ without paying for data as shown below.
Search works the same way as on a desktop computer. Search for the weather, live cricket scores, lyrics, recipes, news or
whatever else the Web has to offer.
Free Zone gives you Google search results and access to all the Web sites mentioned in search results. Eg. If you search for “cricket scores” you can click on the search results to see that page, whether it’s on Cricbuzz, Cricinfo or any other relevant site as shown below.
If you want to use Gmail or Google+, sign in with your Google account and send emails, post updates and check your inbox without incurring data charges. If you don’t have a Google account, you can set up an account in Free Zone to get email and access to
Google+ as shown below. 
Free Zone also offers you ways to access the entire Web beyond Free Zone. From a special page, you can become a subscriber or use the balance on your prepaid account to surf the Web, beyond the sites you could reach from search results. So long as you see a green banner reading “Free page,” you’re paying nothing.
Airtel FreeZone Didn’t Work for Us
Typed www.airtel.in/freezone in Opera Mobile Browser and hit go. This is what we got,
http://10.5.45.120….
A page on the public internet requests data from your private intranet. For security reasons automatic access is blocked but you may choose to continue.
When Chosen to Continue, ended up with
Invalid Address
You Tried to Access the address opera:crossnetworkwahttp://10.5.45.120/wps/portal/operalower which is currently unavailable. Please make sure that the web address is correctly spelt and punctuated, then try reloading the page.
Google and Airtel should have at least tested rigorously before rolling out. Pathetic Experience