Interesting note: in digging around Wikipedia today, I found an article about the USPublic Domain Enhancement Act
, which has been introduced in Congress twice (108th and 109th) and hasn't passed yet. It requires a nominal tax to be paid to keep copyright registered, hence allowing tracking of copyright holders so rights can be negotiated. If the tax isn't paid, the work goes into the public domain automatically 6 months later. Time to get it going in the 110th, I think.
(And while we're at it, we need to tell our congresscritters how much we hate the "PERFORM" act, and pressure them to vote it down.