Sorry to hijack your thread nick, I genuinely mean no offence by it (just trying to help), but I thought this would be a good place to point out for the benefit of our fellow iPhone loving giffgaffer's that in the "How to giffgaff an iPhone" thread on page four I have posted a file that will sort all of the giffgaff iPhone settings out just by installing that one file! It includes the sexy giffgaff logo, internet and MMS, the correct voicemail number, and lots of bonus one touch settings like checking your credit and stuff like that.
I love this place I really do, the fact that there are so many of us all willing to help each other out so much! Brilliant isn't it?
EDIT: I've now done my instructions as a video tutorial, see my signature below for the details.