I was just wondering like others may too; I have an iPhone 3G and used to pay £35 a month for 600mins, 500txts, unlimited data, MMS messages used to be counted as 4 txts off your allowance. When my 18 months contract was up i decided to switch to the O2 Simplicity plan. £20 a month for 300mins, unlimited txts, unlimited data but (which i failed to check beforehand,my fault) 20p per MMS. Now that the iphone 4 is due out on the 24th and the fact that compared to my original £35 plan it has got much worse:- 300mins (instead of 600) Unlimited txts (ok better than 500 but never really went above this) 500mb data (compared to unlimited this is a shocker) 20p per MMS (instead of counting as 4 from allowance, some people don't use MMS, i do!) SO:- I just wondered if i was to sell my 3G iPhone (been offered £250 from a friend) and bought the new iPhone 4 PAYG would i still be able to use my existing simplicity contract to carry on getting the unlimited data? Or as it is a 30 day rolling contract would O2 just give 30 days notice to change of terms, knowing that people may opt for the option i am considering? With the introduction of more data heavy apps, Face Time (which will eventually be 3G too), youtube, catchup tv etc more and more people will need more data. Over the last 2 years i have used an average of 460meg a month, to some this may seem alot but this only consists of looking at Youtube vids with friends at work and checking social networking sites, i wouldn't consider myself an heavy user as at home always use wifi. I just think that there is some sort of price fixing going on behind the scenes as all the networks now seem to be offering very similar deals on iPhone contracts and caps on data. This is something being discussed by many forums and before i head off in an other direction i will stick to the enitial query of:- [If i kept my simplicity plan and bought iPhone 4G on PAYG would i keep my unlimited data until i chose to cancel rolling contract??