Here is a HS language arts example (its vs it's) of a student video podcast posted on an educational blog. It's from Joyce Valenza's HS blog in PA:
http://springfieldvideo.edublogs.org/2007/03/01/its-vs-its/

Something new you need to know about Edublogs - most experts are recommending you DON'T use it - they have begun linking random words in blogs to ads. It looks like a word is underlined for a dictionary or a Google link, but it takes you to ads!