Multiple reports of 3G iPhone chaos suggest that Apple and UK carrier O2 have again seriously misjudged launch strategies.

Early today we reported that full details of O2's price plans for the 3G iPhone were now online, with Apple's UK partner revealing the specifics of the monthly tariffs it announced last month. Existing iPhone users were promised an easy upgrade path through registering online. On a first-come, first-served basis these customers would then have their shiny new 3G touchscreen smartphones delivered to them by courier on Friday.

But, apparently within minutes of the pre-reg site going live, all hell broke loose and very few customers could get past a slew of disappointing screens.

The Register reports that customers were presented this morning with error messages on the O2 upgrade site after filling in forms and told to contact customer services by telephone.

Reader Carol Dew commented that she was "advised that they couldn't take telephone orders until Friday, and they were very sorry for the inconvenience, but they had 2,000 other people just like me calling them this morning, and their managers had advised them that the site was overwhelmed. Because they didn't anticipate the demand."

Macworld is also reporting O2 iPhone ordering system creaks, strains.

Have you managed to upgrade your iPhone via online ordering, or are you another victim of Apple/O2's apparent incompetence to even handle its existing customers with due care and attention?

Let us know by commenting here!