A must read for people travelling abroad from the US and want to use their cellphones. http://www.nytimes.com/2007/03/15/technology/15basics.html?em&ex=1174190400&en=9913a4480bfb4ce1&ei=5087%0A

In India, the cellular phone system used is GSM. You can get a temporary (for the duration of your stay) SIM card which will work with your unlocked GSM cellphone - of course, you will get a new Indian phone number with the card, which you will need to communicate back home. To arrange for this SIM card, you can get one at most India international airports in the arrival area, or ask for your hotel or host in India to arrange for one.

I will be out due to personal reasons from Feb 5th to March 15th