Hi all, I am undecided at the moment if I should go with O2 or Vodafone for the iPhone 4 (will be queuing outside a local store). I am currently with O2 but am considering switching because I have no reception whatsoever at my parents house (where I spend a reasonable amount of time for various reasons). I also have a mediocre signal at home (Calls are occasionally patchy, I can send & recieve texts ok, but only gprs data (although I do have wifi)). I finished my contract back in January this year and am currently on the Simplicity £20 a month iPhone rolling 30 day contract. I am considering for this reason Vodafone, especially if the leaked prices earlier this week are correct. However, before entering into an 18/24month contract, i'd quite like to test the signal strength both at home and my parents and see how good it is. I have here a PAYG Vodafone sim card, with credit, but no phone to put it in. So onto my question........ If I ring O2 and ask them to unlock my iPhone 3G and I then put my Vodafone sim in will I lose all my settings, apps, contacts etc off the phone? Basically will it wipe the phone so I have to start again? Everything is backed up on the laptop but it would be the hassle of losing everything. Or If I ring O2, they unlock the phone and I put in the Vodafone sim it just converts to the Vodafone network and I keep everything on the phone as is? If this works then I might also pick up a free Orange and T-Mobile sim and try a comparison of the networks prior to launch so that I can make an informed decision. All help appreciated please. Thanks.