If you need to transmit photos from location shoots then it's a good idea to use the mobile phone operator with the widest coverage, and in the UK that's O2. But to be able to use an O2 phone with a laptop you need a monthly subscription. You can't use pay-as-you-go.

(Going with a different service provider on pay-as-you-go isn't really an option as data calls are billed at a ridiculous rate, sometimes as high as £14 per megabyte.)

When the iPhone launches in the UK in November it will be tied to O2 and you'll need to sign-up for an 18-month contract costing a minimum of £35, at least until someone hacks it. But the up-side is that you'll get unlimited data transfer, which could make it ideal for anyone who needs to transmit large files when they aren't in reach of a wireless Internet zone.

More info in this BBC news item.