The iPhone 4 now available on 3 and T-Mobile

T-Mobile’s prices are roughly in line with that offered by its competitors Orange, O2 and Vodafone, with 24 month long contracts starting at £25 if you buy the 16GB device for £279 up front.

You can get it for free, but you would need to pay out £60 a month. 3 offers a better deal here, giving you a free iPhone 4 if you pay £45 a month.

But the networks will lock you into a contract for two years, while competitors offer 18 month contracts and it is possible to get an iPhone 4 sim-free from the Apple website which can end up a whole lot cheaper.

It is also possible to get a 12-month option from Tesco Mobile, which uses the O2 network.

The iPhone 4 is very much a success, and it is still very difficult to get hold of the device from Apple, which has a three week shipping wait.

It has suffered much-publicised antenna problems, but this doesn’t seem to have hurt sales much.