I have an Arduino Uno and a GSM/GPRS shield with a giffgaff sim card (on the o2 network?). I have successfully sent texts and made phonecalls, but when I came to the GSM web server example, I need the APN, login and password for my provider. I have found a couple of different lots of details, but I am repeatedly getting the 'not connected' message. Is this due to the APN etc. being wrong or what? If so what is my APN ect? Please excuse the ignorance.
Are you in the UK?
If so, this page has a list of APN settings: