Mike Mace has written an excellent article on different attitudes to mobile phones on either side of the Atlantic.
I would say that one of the differences is that in the states they have a network with the same quality as we had in Europe about ten years ago in terms of coverage. The other factor is that Mobile Data to an American is the Blackberry for E-Mail, and whilst SMS/MMS are starting to happen they are also "supported" by advertising.
I guess when both countries are using the same standards for phones we can look at both areas and see how the two markets can converge. Most of my European work mates call their phone a "Handy" and that is just what it is to them, it is the device that allows Wireless Foundry to compete with bigger firms because we are available directly rather than clients getting lost in voicemail hell.
What I would say is that Europe does have the same geographic differences as America. Talking to executives in Germany they say that too many users keep their phones switched off using it only when they have an "emergency". Thus the key performance metric for the networks is now the rather rough measure of Minutes of Use rather than ARPU. When you talk to Italian Networks they will speak of the need to migrate customers from Pay As You Go to Contracts in a country that is fast becoming one in which most people own more than one handset and fashion means that they change handsets as often as the update their wardrobe.
The post has got me thinking and time permitting I will try and write a longer piece myself on national differences to mobile use. On one of my first trips to Japan what I noticed was that talking in public on the phone is a social faux par, which I guess explains why they have such high data useage rates.