I would say that calling cards are probably the best option in making international calls to India.  There are many brands and prices of calling cards that can fit any budget.  The competition between such cards helps to provide the consumer with some fairly cost effective measures.  For example, for 20 US dollars, one can get up to 200 minutes on a calling card.  This would cover about three plus hours of talking.  There are other rates that are as, if not more, competitive.  I think that this might be the best option to follow.  If one possessed a cell phone that can make international calls, depending on the package of minutes purchased, this might also be another avenue to pursue.  The other option would be to set up a Skype system or Yahoo messenger between your friend and you, allowing you to talk at length without minute measured cost.