TeaShark, a mobile browser like Opera Mini, allow you to access Airtel GPRS for FREE.
Shockingly it has nothing to do with modifying any Airtel settings or any kind of hack.

Here is how I used this…

* Download TeaShark v. 312. Its free and being JAR file it can be installed on most handsets.
* Open it from your mobile and select AirTel Live as access point.
* That’s it! Open any site from TeaShark and you won’t be charged anything.

Note for the first time, when TeaShark starts, it may take more than one minute to initialize. Also this one time initialization may fail many times. But don’t loose your heart!

As of now, this trick is limited to handsets only.

Note : “Subscribe to Packet Data First”
This means you need to activate AirTel Live service which is free.
Contact customer care to get it activated.
Also select only AirTel Live as access point when prompted by TeaShark.

Download TeaShark :
http://teashark.com/download.html