[adw]

A lot of this reads like the FOAF, DiSo and Semantic Web visions. None of those has got much traction in the market: my gut feeling is that there is a market in portable identity somewhere, but no-one's worked out what it is yet.

I'd be tempted to start with the mobile companies, though: they already know who I am, where I am and how to bill me. Feels like a natural place to add authentication and identity broking...