The Nook Simple Touch is an android-based eReader. In their interface for reading books, you can highlight a word or set of words, then attach a note to that.
The notes are limited to 512 characters, but you can have an unlimited number of notes for a book. I currently work around the limit by highlighting a word, writing the note, then highlighting the next word and continuing the note.
Is there a way to remove the limit of 512 characters, or increase it to a very large number? My nook is fully rooted, so I imagine it is a simple config file or sqlite entry somewhere, but I don't know where to look.