Apologies if this has been discussed before (I didn't have much luck with the search feature. I am about to come to the end of my first year on PAYG with o2. I have a 3GS and basically now want the cheapest tariff I can find. I'm not a heavy texter (300 is more than enough) and I don't make many calls but obviously I want the internet. 500mb should be fine. Ideally I want to stay with o2, so my main query is does anybody know if the standard simplicity will work in the iPhone, rather than the designated simplicity for iPhone, obviously because the standard one is cheaper. And if not simplicity, is there anything else I can do cheaply on a PAYG basis? Help will be much appreciated.