Update (Jan 03, 2010) : Vodafone IN Kerala is another bad apple, enable DND service by sending SMS with 'START DND' to 1909 or call 1909 for more information
Update (July 17, 2009) : !dea kerala is perhaps the most disgusting mobile service providers. It overwhelms its subscribers with pre-recorded voice calls and SMS about latest offers. To request DND service give a call 1909.
Update (Sep 26, 2008) : Airtel users in AP can enable this feature by using service commands too. Call "*121#' and reply with number '4' to select Do Not Disturb feature and then reply with '1' or '2' for start or stop the Do Not Disturb settings. Also you can get your registration number which is need in case you would like to file a complaint.
Somewhere between Wordsworth and Browning my cellphone starts to ring, I answer the call and hear yet another recorded voice tempting me to try their Airtel hello tunes service or some lame duck offers. I think I had enough of this, I called the 198 customer care number and registered for the Do Not Disturb option. The Airtel Bharthi Andhra Pradesh call center guy assures me that it will take effect in next 45 days(duh!).
I understand that businesses need to sell but not at the cost of your time and privacy. What irks me most is that people's apathy towards the National Do Not Disturb scheme. I guess its more lack of awareness or just laziness ?. It takes only few minutes to call and add your number to listing , you send SMS or register online as well and put end to at least some of these stupid calls. It may be yet another policy that may not work, but how will you know if you don't try it? .