You can see a demonstration of the generic Blacklight plugin at http://demo.projectblacklight.org
DTU Findit - http://findit.dtu.dk
This application superseded the Historical State application which was also a Blacklight application. http://d.lib.ncsu.edu/collections/
The UI component of the Hydra Framework - http://projecthydra.org
"Highly Relevant Search Result Ranking for Large Law Enforcement Information Sharing Systems", presented by Ronald Mayer of Forensic Logic at Lucene Revolution 2011 - Blacklight was used to quickly provide a proof-of-concept on law enforcement data.
Podcast: Project Blacklight, Hydra and Libraries in the Digital Age Interview with Bess Sadler for the SolrCluster podcast. Origins of the Blacklight software, the Hydra Project, some of the challenges facing libraries with regard to search and management of digital content, and future Blacklight development projects like Spotlight and GeoBlacklight are discussed.