This are the steps that you must follow (using Trook):
http://dearauthor.com/wordpress/2010...-opds-dropbox/ till step 6.
1. Use the Default mode
2. Chose TROOK in the compatibility level (last dropdown)
3. Press button Generate the catalogs
4. Exit Calibre2opds
Nook Side
1. use Trook
2. Go to My Feeds
3. Open using url from catalog.xml´s dropbox. Something like...
http://dl.dropbox.com/u/123456/YourF...og/catalog.xml
4. Bookmark it
5. Refresh... and voilá
You got a cloud e-book library on your Nook.
If you want to browse your books using the Nookdevs Web Browser follow this nice tutorial from user sarasbloke ->
http://www.nookboards.com/forum/index.php?topic=3263.0