With Orange, prices start from £30 per month and go up to £75, with handset costs sliding in the the opposite direction from a high of £270 for a 32GB iPhone on the cheapest tariff to a freebie 16GB piece of hardware on the top line tariff. Like we said, it's complicated.
There are also pay as you go plans, capped at 250MB data per month. The 16GB will set you back £480 or you can plump for the 32GB model for £570.
Mobile web addicts will be pleased to hear that all the pay monthly plans include unlimited data (with the usual caveat about fair usage, although – at 750MB per month – it is actually fair). Full details here.
As for O2, it charges more for the iPhone on a 24-month contract than for those on an 18-month contract, but the monthly payments are £5 less than on the 18-month deals.
More after the break
You'll pay anything from £323 to £29 for the iPhone 4 32GB, depending on your tariff (from £25-£60/month on the 24-month deal), and £279 or less for the 16GB model (it's free with the top tariff). O2 has also abolished its unlimited data plan. Full details here.
Vodafone has yet to confirm its price plans, although they were leaked online earlier this week.
You can also buy the iPhone 4 SIM-free on the Apple website for £499 (16GB) or £599 (32GB). Yesterday the company announced it had more than 600,000 pre-orders for the phone, leading to delivery delays in the US and UK.