Today's resource is a new site that makes public domain legal data searchable: Openjurist.com. Open Jurist is a legal database of U.S. Supreme Court opinions and, more excitingly, United States Courts of Appeals opinions (via the Federal Reporter), which, to my knowledge have never been available online outside of LexisNexis Academic Universe and Westlaw. FindLaw has some Federal Court of Appeals opinions online, but only from 1995 to the present.
Another non-subscription case law resource is AltLaw, a project of Columbia Law School's Program on Law and Technology and the Silicon Flatirons Program at the University of Colorado Law School. AltLaw also contains searchable and browsable opinions of the U.S. Supreme Court and the U.S. Court of Appeals, but only has opinions from the second and third series of the Federal Reporter, whereas Open Jurist also includes the Federal Reporter, first series dating back to 1890.
Great new developments in making public domain knowledge truly public and accessible! Hat tip to our government documents librarian Danny Luce for letting me know about Open Jurist.