Which mobile operator is best for Apple's iPhone? That's the question now uppermost in the minds of potential new iPhone owners and O2 customers nearing the end of their contracts. O2's two-year exclusive iPhone deal with Apple has been publicly exploded with news on successive days.

Yesterday Orange confirmed it will stock the handset as O2's exclusive two-year deal with Apple to offer the iPhone has expired. The announcement follows months of speculation as to whether other UK networks would be able stock the handset. Vodafone quickly followed in the footsteps of Orange after it revealed today that it will also sell the Apple iPhone in the UK. O2 responded yesterday stating its continuing relationship with Apple, but also promoting the rival Palm Pre - for which it has UK exclusivity.

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A price war is widely expected, but maybe just as important is each carrier's depth of faster-data access via 3G communications.

In July Ofcom (the Office of Communications, an independent organisation that regulates the UK's telecommunications and wireless communications sectors) released 3G coverage maps by mobile operator - showing which mobile operator has the best 3G coverage.

UK 3G coverage maps Ofcom iPhone

The 3G coverage maps were prepared in January 2009. They represent the area where Ofcom assessed the mobile operators met a minimum coverage threshold.

The carriers compared by Ofcom include 3, O2, Orange, T-Mobile and Vodafone. Only mobile carrier 3 has yet to announce plans to sell Apple's iPhone.

The shaded areas on the maps indicate areas where customers have the possibility of making and receiving a call outside over a 3G network (although with no guarantee of being able to do so).

All operators produce their own coverage indicators on their websites, which are likely to provide more reliable guidance to network availability in any given area, says Ofcom.

The accuracy and detail of the Ofcom maps are not to the same level as the mobile operators publish, admits the regulator.

O2 has been plagued with data-access outages in recent months, although it cannot to estimated how the other carriers will fare when supplying the far greater data needs of the iPhone customer.

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