10 quid a month for unlimited data doesn't sound too bad a deal, especially as 02 are allowing tethering, that's cheaper than most of the 'Mobile Broadband' dongles out there.
Do you have a source for that? I was under the impression they would not allow it, plus there was no way of connecting the iPhone to a laptop to use the data connection anyway. I would love for that not to be the case, I would make a lot of use of that!