DMN has been posting a series of articles on the legal issues that can surround podcasting. They are up to four parts already, with each part tackling a different aspect of podcasts.

Part 1 - The First Amendment and risk of defamation suits for expressing your opinions
Part 2 - Utilizing music in your podcast
Part 3 - Laws surrounding recording telephone conversations for podcasts
Part 4 - Lawsuits and their possible chilling effects on podcasters