I could definitely see something like this being useful a forum moderator too. Right now I bookmark things for a mix of reasons, no real order to it, but I might use it more productively if I could bookmark some things as “follow up later”, some things as “useful resources I personally want to remember”, other things as “great topic to link to in future newsletter” etc.
Another potential solution here could be bookmarks + tags perhaps? Haven’t used tags yet on our forum so not sure current limitations but perhaps a plugin…could allow users to mark posts with their own private tags, visible to no one else, maybe namespaced to username to avoid conflict w/ more global/public tags. Just an idea, not sure if it’d be easier or harder to implement that way vs. actual folders.