I got a Zune (www.zune.net) about a year and a half ago and have been quite happy with it. One of the major features that was lacking was the ability to save your place if you were listening to an audio book. I spend a lot of my time listening to self-help audio books and religious audio books. In order to keep track of my place in the audio book I realized I had two choices: just listen to one audio book and nothing else since the Zune remembers your last listening location, or have my audio books have many small tracks and try to remember the track that I was on.
As you can imagine, both of these methods have serious follies. I looked online to see if there was some sort of hack that could provide some sort of bookmark functionality, but didn't find anything of value. I did, however, stumble upon a forum post where someone suggested that you put your audio files into the Podcast section of your Zune. I realized that the Zune keeps track of your last listening location in each of your Podcast episodes. I immediately tried to drag files into the Podcast section of the Zune software, but it didn't take.
After a lot of investigation and trial and error, I found that marking the mp3 as an "ITUNESPODCAST" (iTunes podcast), if you drag it into your Zune software under music, it would immediately recognize it as a Podcast.
Here's how I did it:
First, download Mp3Tag (http://www.mp3tag.de/en/download.html), which is software you are going to want regardless. Mp3Tag makes it SOOO much easier to tag your mp3s with proper information about the album, artist, song, etc.
Second, you're going to want to change a couple settings to make Mp3Tag a little easier to use.Set Mp3Tag so it doesn't annoy you every time you save mp3 tag information:
Under Tools-> Options-> Messages
Now make it so Mp3Tag will auto-save everything you change so you don't have to manually save every time you make a change:
Under Tools-> Options-> Tags
Third, open the mp3 you will want to add by either dragging it into Mp3Tag or using the open dialog.
Fourth, add the ITUNESPODCAST=1 extended tag to the mp3 by right-clicking on the mp3 in Mp3Tag and click on "Extended Tags..."
You can also set up your other tag info (you will mainly be concerned about the Title and Album information) for your Podcast file.
Fifth, just go to the 'Music' section of your Zune software and drag your quasi Podcast file into your Zune software, or put it where Zune will pick it up, and you now have a Podcast file that will save your place when you listen to it!