Simon Grice has put up a blog aggregator called Personal Digital Identity (which Simon calls “PDI”). I get the clear sense that since last October’s Digital Identity World, PDI has been coming into its own as a distinct subset of the digital identity space. From an XRI/XDI perspective, this makes sense, as individuals are the ultimate authorities, and thus the reason for the “=” i-name/i-number space in XRI architecture.

But just as “=” is only one of five global contexts in XRI (organizational – “@”, general – “+”, special – “$”, and physical – “!” are the other four), my gut is that PDI will only be successful as one facet of the “identity metasystem” that Kim Cameron posits will be necessary to achieve ubiquity.

Still, it’s significant that a critical mass has formed around the necessity of this particular facet. Because, as Kim’s First Law implies, PDI is the sun around which the rest of the metasystem planets must revolve.