Adam Weiss writes "I am the creator and co-host of The Puzzle Podcast, a short weekly audio puzzle in the spirit of the Car Talk Puzzler and the NPR Sunday Puzzle. [For those of you who can use it, here's an iTunes link in case my site gets completely Slashdotted.] The puzzles we pose are from all genres, but so far, most of our puzzles come from books and games that are available commercially (we have of course been giving credit). I would love to be able to present our listeners with some puzzles that are in the public domain (or Creative Commons licensed) for variety and to support independent puzzle makers. Does anyone know of an online source of puzzles that would fit the bill?"