If your friends having airtel connection. Which number starts from 9900.. Then just remove first 9 ( then it become 900... ) and send message to that number. It will go free.
it works in some of area, check in your area...
Be carefull if it is not work in your area then 3rs will deduce for each message from your balance so try once and check balance...
Please leave a comment if it work in your area, let others get benefit from this :-)
