MSReader only opens .lit files. You can convert a word document to .lit with a free addin for Word 2000/2002 from Microsoft.
Palm's reader can read .pdb files and some others. There is a version for PPCs at their site.
Peanut Press
Haali reader can read a lot more, but not .lit
Haali.
Media player I will defer to a multi-media fanatic for you, I know it plays .wma and .mp3, maybe .wav. Don't know about film clips. I used PocketTV for the one clip I experimented with.