If you are travelling to the US, one of the big questions is what to do about a SIM for the mobile phone. Continuing to use the India SIM is out of the question with roaming charges at Rs 150 per minute. Of course, one could use the Reliance calling card, but that still doesn’t solve the problem of mobility.
The solution I used (thanks to Atanu) was the T-mobile $50 monthly plan for unlimited calling, SMSing (both within the US) and web browsing. The GSM SIM can be put in the phone and you are all set. Combine that with a Reliance calling card (virtual), and you have telecom costs completely under control and full mobility!