O2 are changing call charges outside the bundle of minutes included in your iPhone Price Plans from 12th July 2010.
This change in call charges constitutes a change to the terms of the contract between O2 and you, the customer. Therefore you are free to be removed from contract without penalty.
The changes in rates are minimal but you might just want to get yourself out of contract.
Act fast though because if you do not contact O2 requesting to be removed from this contract in advance of 12th July you will be assumed to be accepting of the change in terms.
All info available on O2.ie under 'Terms and Conditions'