I'd also love an app to go through my phone numbers and internationalise them. It would have to be a semi-automated process, as I've got contacts with local numbers in a number of different countries.

The Google Contacts support is currently one way, but it's a great idea to write the data back. Could you please vote on it here: http://rapportive.com/feedback/527051 — that way you'll be kept in the loop as we make progress :)

What mobile device do you use?