Ok guys i have seen a few posts about this but i have a question, So i have heard that you can keep your iphone by doing the following

Pay for the first month of contract
Pay for the price of the iPhone
Pay the ETF

So say i was looking to get the 8GB, so i would:

Pay for the first month of contract: £30
Pay for the price of the iPhone: £99
Pay the ETF: £??

So does anyone know the ETF for O2 UK?

Thank You