Quote:

Once you receive your iPhone 3G, you'll need to to connect it to your Mac or PC to finish activating it and to sync your information. Find out more

iPhone is restricted to use on the O2 network unless you are roaming. If you do not enter into and remain in an airtime agreement with O2 on one of our tariffs for iPhone, you will not be able to use the phone functionality of your iPhone. If you attempt to unlock iPhone and use it on another network, it may become permanently unusable. Making unauthorised modifications to the software on your iPhone violates the iPhone software license agreement, and the inability to use your iPhone due to unauthorized software modifications is not covered under your iPhone's warranty

So looks like you could buy one online and not sign up for an airtime agreement... ie they think it will be always locked to O2

Do they not read the internet or do they rely on the fact that most buyers will be blissfully unaware of the unlock