Currently this services is limited to Nokia phones powered by symbian [sounds too technical then have look at the supported devices]
Sadly this feature is not available for the S60 3rd Edition users.
I haven't used this service since i have a 3250 :| but going through the features and how the service works, i would say that is would be a symbian C++ application which would act as a default SMS application on the Symbian Phones. The application is developed by an UK based Affle
If you are already excited about this service then hold on their is much more to some. SMS Social Networking
2008 starts with a very Sweet simple yet colour full service from Airtel. lets wait and watch what 2008 have for us.
How to get this service activated?
Simple, type SMS2 and send it to 543210 or 59191
Note: This services is available for Airtel customers only. And on selected handsets.