Yes you do not need contracts to own the iPhone 3G and new iPhone 3G S, the prices are as follows below.

iPhone 3G 8GB will cost you £342.50, the iPhone 3G S 16GB will cost you £440.40 and the iPhone 3G S 32GB at £538.30. When you buy the new iPhone from O2 you will get 12 months of unlimited web and Wi-Fi which is called the O2 Web & Wi-Fi Bolt On, you can keep this until the end of the 12 months for £10 a month if you like.

To get the 12-months all you need is the new SIM that comes with the iPhone 3G, if you are already with O2 Pay & Go you can easily transfer your number to the new iPhone. Pay & Go does not give you Visual Voicemail, Internet tethering or call merging, unlimited data and Wi-Fi applies to use in the UK only,

Tariffs:

• Top up £10-£14 and get 500 minutes
• Top up £15-£29 and get 1000 minutes
• Top up £30+ and get unlimited minutes

Check out the contract tariffs