If you copy Mobipocket files over manually rather than using the Mobipocket software in Windows, they don't actually have to go in the Mobipocket folder, and can be sorted in with your other formats. (Just plug in the USB, open the iLiad as a device from the desktop, and drag files over into the Books folder).
I use the inbuilt software (the little icon that looks like a label) to edit the file name to the title of the book (you can get rid of the file extension, and the iLiad's software will still deal with it quite happily -- but you have to do it on the iLiad, don't remove the file extension on your computer!). Then I make the second line the author's name (last name first). Then if it's part of a series, I use the third line to put series and number. So things look like this:
Lord Valentine's Castle
Silverberg, Robert
Majipoor 01
Then using the sort criteria (the little icon on the left in the File Manager that looks like a filetray), I set it to sort by information tags using the Description button. That will sort by author, with books in correct series order. If you want to sort by title, use the File Name button instead.
If you've got a few hundred books to catalogue, this may take a while, but once they're all done it's a trivial matter to do it for a new book when you add it.
Hope this helps. (I think I must have been a librarian in a previous life).
