I usually listen to audio books and 4 hour long radio programs and it would be nice if the iDevice had a feature that allowed me to bookmark audio files. So is there a way to do this?
Hmmm, question. Are the audiobooks in audiobook format, or as mp3s? According to this little blog entry, if it's in the right format, you can at least add chapters.
Use the link I gave you and convert the mp3 to audiobooks. That's where your problem is. I'm pretty sure you can bookmark your audiobooks.