Network Provider O2, have announced iPhone 4 upgrades for existing iPhone users. According to a report from PCPro, those customers with mobile contracts can leave the contract and get a brand new iPhone 4. However, they'll have to pay £20 per month for the remaining months of the contract.

The new Apple smartphone will be available with either an 18-month or a 24-month contract. The tariffs are yet to be announced.

Existing iPhone users can as well turn in their handsets to O2 for recycling. The network provider will reportedly be offering £240 for the 16GB iPhone 3GS and £253 for the 32GB iPhone 3GS.

We are yet to hear from Orange, Vodafone and T-Mobile regarding their iPhone 4 deals.