Originally Posted by glukkon
with ADE do you mean Adobe?
I only have epubs without Adobe Digital Editions
Yes, "Adobe Digital Editions". You can open epubs that don't have DRM in ADE. And, as far as tell, most ereaders that support epub use ADE to do this. This is why they can read epubs that have Adobe DRM. What I was thinking is that you could copy the annotations file from one ADE based device to another.
An experiment with my Kobo Touch and Kobo Glo worked. These are running the same firmware version. Putting the annotation on the PC for ADE mostly worked. The annotations were in the list, selecting them went to the right place but the text wasn't highlighted. Creating a new annotation in ADE on the PC and copying the file back to the devices worked properly.
I don't have another ereader to test with. But, if they it uses ADE and the directory the annotations file is stored in, there is a good chance the above would work.