I started recently to use calibre news on my iPad without 3G connection.
I soon faced the problem that bookmarks could not be synchronized between iBook and any other software.
My 2 penny solution (applicable to all iOs device, as far as I know): copy the article URL that calibre append at the end to a
Simplenote note.
Now I can see the up-to-date version of the interesting article I've read. Example
here .
To extend the solution I wrote a Yahoo!Pipe (
here) that convert the note in a RSS feed, that can be used in your favorite feed aggregator or imported in Instapaper.
Feel free to use or copy the Pipe and to post comment and criticism!
Cheers!