thanks for that, my version is 2.2009.51-1.205.1 so its a vodafone with the "205". I could chance it by buying a pay as you go O2 sim (no doubt around £10-20 from a high st store if available), but then if prices are the same no matter what network I send to (on a no contract phone) then Im not too fussed. Ive almost always used a phone primarily for texting, and pay as you go is just too expensive to use for anything but short calls. No doubt vodafone do their own deals if youre topping up often, as with O2, but Ill need to find that out first if they state it on their website or on any no contract mobile price comparison sites.

From previous posts it would seem that I could call vodafone and they would take me through the process of unlocking the phone if required for no fee, if I couldnt find the same thing online- but the easy thing to do I guess will be to just put a friends O2 sim in the phone to see if its works.

thanks