Actually, while that is of note, it's not necessarily 'the most important', and probably not the most difficult or interesting. We do pretty well with e-mail and web-pages stored on remote locations. That's definitely a starting point. Data services fit into the ubiquitous computing model like any other. Don't like where your data is stored? Migrate it. Have this done automatically. The ideas mooted here do make the ownership issue more acute, but they hardly raise the questions for the first time.

Henry