Carphone Warehouse are obviously trying to get rid of the 16GB 3G models of the iPhone before it is superseded by the 16GB 3G S. This is available online and offline.
The following table shows the difference between each contract available with the iPhone.
o2 allow you to change your contract after 9 months, this means that it is sometimes cheaper/not much more expensive to take out a more expensive contract per month, to allow you to save money up front on paying for the hanset. (This was initially pointed out on MSE - [http://www.moneysavingexpert.com/deals/cheap-iphone
] but the image below also accounts for the new 3G S phone.)
The contracts this applies to are highlighted in grey.
Also, Red = Only available from Carphone Warehouse and Blue = Only available from o2.
Remember cashback sites Quidco/TopCashBack for £30-£45 as well.
Feel free to vote this cold, if you know of a better deal.
This site is to find the best deal on a specific product available,
Eg. 6 x Coca Cola cans for £1 would get voted hot, not cold because you can get 6 x Roller Cola cans for 50p elsewhere.
Hope this helps anyone looking.