I bought a 3G Prepaid SIM from Mangalore where they claimed that its national roaming. So 3G was supposed to work all over India. but now I am in Mumbai and I just cant connect to 3G. I tried several debug techniques on my Galaxy S Captivate.But I do remember one conversation when I was purchasing the SIM card, the guy knew that 3G would work in South Zone but was unclear about all India roaming. Then he called up his superior and told me that it was now works all over India. Seems to me like its still restricted to each zone.