This weekend the is the launch of Registered Commons, a registry for fingerprinting and timestamping service for material with a creative commons license.
Registered Commons is a secure timestamp service for the Open Content community.
The point of the service is to offer creative commons licensers and licensees better identification of the author of particular material, of the publishing time, and of the licensing terms – e.g. for commercial alternatives to a non-commercial license. Probably the most important thing about the project is offering licensees a single place to go to when clearing the copyright on large amounts of material.