I think that podcasts are a great tool for life in general, but also for the classroom. They are also easy to make (I made one for some book talks I had to do for another class). Courtney, in "Library 2.0 and Beyond," offers some great ideas for their use. She mentions booktalks, using them to enhance displays and exhibits, making individual librarian podcasts as an audio-blog, using them in library education and instruction, as well as conveying local history, story time, and tours (37-43). Here are a few I found and their implications for the classroom...
SHAKESPodosphEARE - podcasts designed to go along with the study of Shakespeare, or if you just want to hear him on a long car ride :)
Just Vocabulary - a 4 minute podcast offering new vocabulary words each day
Poem of the week - offers a new poem each week
Courtney, N. (2007). Library 2.0 and beyond.. Westport, CT: Libraries Unlimited.