Open Researcher and Contributor ID: ORCID
ORCID is a non-profit effort to create unique identifiers to differentiate between researchers with similar names. Researchers register themselves for an ID and may include as much information beyond the minimum as they are comfortable sharing.
ORCID is free, there is no charge for you to create your ORCID ID.
Why should you care about ORCID? A number of publishers will require an ORCID ID starting in 2016, including Science, IEEE, AGU, and others.
Register for ORCID