I have seen few providers offering this service (free sms from pc, ofcourse ad supported) here in India like (atrochatro or way2sms etc), we want to know how it is done, there are some php scripts avaliable but do they work for India, what to do for getting gateways from operators, we would love to give this service on our websites, what is the easiest way to approach this and what all are the requirements?