Just a post concerning the sending of SMS from Php Script.

In order to send a SMS (texto) via PHP, it is necessary to use an API allowing to request with a SMS gateway, which is the interface between Internet and GSM mobile network.
How it works ?
Some gateway work easly via sending of emails with an address like 06xxxxxxxx@orange.fr (number@operator). Then, the gateway will then connect to an SMSC (Short Message Service Center) which will Transmit the SMS on the mobile telephone network.
The SMS sending is not free, the SMS gateway providers charge a few cents per SMS sent.

Some resources concerning the SMS gateway :

You can also create your own SMS server using SMSlib (available in Java and .NET) or Kannel.

That’s all!!!