Thanks largely to smartphones, those networks are under greater pressure every day – one streamed YouTube video has the same effect on the network as half a million text messages sent simultaneously, the equivalent of everybody in Newcastle sending a text at once.

o2 Chief Executive

So then why do text messages still cost 10p each (once you run out, as even business tarrifs do not have unlimited) when they are obviously not very demanding on the network?

When I get my new iPhone 4, and switch to a business tarrif, I think I shall switch to an IM app instead of texting.