Following rival carrier Bharti Airtel’s announcement that it would begin selling the iPhone 3GS in India today, Vodafone has announced that it too is offering the iPhone 3GS in the region starting today. Airtel is offering the 16GB model for 35,500 rupees (roughly $780) and the 32GB model for 41,500 rupees (~$913) and is also giving iPhone 3GS customers 500 MB of free data every month for a year from the date of activation; Vodafone’s…