I've got iphone on PAYG with O2 but you have to buy the phone. Top up £15 a month and you get all your O2 to O2 calls and texts free. Internet including email costs £10 a month. There is a limit but I have never reached it and I live on the net. That tenner covers everything, FB access, downloading apps (but you still buy the not free ones) etcet. You also get free wifi at loads of places, macs and starbucks for a kick off you can check the website to find out where else. AND you still have a fiver a month left to spend on calls and texts to non O2 numbers.