This project explains how send request to webservice via GPRS through SIM900 module ( with Arduino UNO) and according to the response of the web service how change arduino outputs.
this webservice is just develop only for explain the procedure. It is not a standard one. I have uploaded the content to the Dropbox and have shared the link with you. please follow the read me file first.
AT comand PDF - http://elecfreaks.com/store/download/datasheet/rf/SIM900/SIM900_AT%20Command%20Manual_V1.03.pdf