on the device, if rooted
you can access
notes and apparently svg-drawings? here:
also some SQlite .db files here:
external microSD holds sqlite databases as well, access on reader::
I can:t find it right now, but i think i saw once that my marked up text and annotations went somewhere into those .dbs.
see mobileread wiki
, and this firefox addon
really is pretty good.
I did search for your library file but couldn't find any.