Thanks for your response...
From your info I understand that using some API, the SMS send screen would appear with the recipient/s telephone prefilled and using SMS URL I can send the SMS content to some third party (based on that URL) to forward the request to the Service Provider.
But I actually wanted an API (if there is one exist in the iPhone SDK

) that can be used in a third party application developed for iPhone to send the SMS with its content to the Gateway of the Service Provider directly and probably not using the way of SMS URL ie forwarding the request to another Third Party and then they fwd it to the gateway.
Please correct me if I've understood or interpret anything incorrectly.
Thanks in advance...