ORDID and ResearcherID and Scopus, oh my!

It is just me, or are there an increasing number of unique identifiers popping up in Library Land? A person can now be identified with any one of a number of URIs such as:

  * ORCID - http://orcid.org/0000-0002-9952-7800
  * ResearcherID - http://www.researcherid.com/rid/F-2062-2014
  * Scopus - http://www.scopus.com/authid/detail.url?authorId=25944695600
  * VIAF - http://viaf.org/viaf/26290254
  * LC - http://id.loc.gov/authorities/names/n94036700
  * ISNI - http://isni.org/isni/0000000035290715

At least these identifiers are (for the most part) “cool”. 

I have a new-to-me hammer, and these identifiers can play a nice role in linked data. For example:

  @prefix dc: <http://purl.org/dc/elements/1.1/> .
  <http://dx.doi.org/10.1108/07378831211213201> dc:creator
    "http://orcid.org/0000-0002-9952-7800" ,
    "http://id.loc.gov/authorities/names/n94036700" ,
    "http://isni.org/isni/0000000035290715" ,
    "http://viaf.org/viaf/26290254" .

How have any of y’all used theses sorts of identifiers, and what problems do you think you will be able to solve by doing so? For example, I know of a couple of instances where these sort of identifiers are being put into MARC records. 

—
Eric Morgan