I have barely gotten used to Twitter (use it to write one-liners, getting news updates and making a plan with friends) and now the mother bird has given rise (or birth) to a brand new desi twitter called SMSGupShup (rhymes with Numsum- Gupshup means gossip). Its by the guys who started Webaroo (the “offline” wikipdia).
Personally, the mobile is a very exciting market for India with the breadth of users spreading from very low-end phones to very smart-phones. India has a far more reach of mobile (about 250 million mobile-literate as compared to 65 million pc literate). SMS is already being used in India for a lot of utilitarian services like sending climate forecast to farmers and selecting best prices for selling their crops/vegetables. A service in India will really be a mass success if it solves basic problems at the rural level or is finanace -related.
Meanwhile, you can read about SMSGupShup on GigaOm. However, I do not believe the traffic numbers that SMSGupShup have published and still believe Twitter has much higher traffic. I have signed up just now and I hope I dont get spammed!