Using the audiobook or podcast genres simply isn't feasible, as they are designed for much smaller numbers of files- There's currently about 400 different books/ radio series on the Ipod, each of which may have upwards of 60- 70 files, all depending on what it is, or the way it was ripped.
I totally agree. The iPod's "Audiobook" and "Podcast" menu items are downright pitiful. They're unusable if you have any type of "Periodical" Audible audiobooks (i.e. daily or weekly releases) since you end up with a single list of HUNDREDS of titles with absolutely NO sub-categorization -- it's just a giant list of hundreds of titles.
All of these are stored directly under Music on the Ipod and then drilled down either alphabetically by author, or by genre.
Sadly, Apple removed this capability on the new "Classic" iPods. Audible audiobooks and podcasts no longer show up when navigating by genre. You now HAVE to either navigate then via the main menu items (which, as already stated, simply doesn't work in certain situations), or via a playlist/smartlist, which of course gives no subcategorization (i.e. you can't sub-navigate by "author" when using this method.) Luckily, this only applies to aa audiobooks -- mp3 audiobooks still show up under the "genre" category. Podcasts, however, don't show up under "genre," and the iPod's "Podcast" navigation puts them in reverse chronological order, meaning that when one finishes, the PREVIOUS one starts playing. It's ridiculous. At this time, the ONLY way to have Podcasts sort in ascending order on the iPod is to use a Smartlist.
I'd use a slightly different approach- Not all files tagged with the audiobook genre will necessarily want to have the position remembered, depends on what it is. Instead, I'd use a library flag/ field for bookmark-able yes/ no; Thats that little bit more flexible, without making things too complex.
I agree that it should be an editable tag. However, I strongly feel that audiobooks and podcasts should "default" to being bookmark-able since I honestly believe that 99.9% of the time, people will want these genres bookmark-able. Frankly, I can't think of a situation where you wouldn't want an "Audiobook" to be bookmark-able. In what situation would you not want this? That aside, what I'm advocating would still allow you to "un-check" the bookmarking capability on these files.
Larry