[tablespoon]

> And if your collection is seen as useful to some people in a couple decades isn't really easy to tell. Depends on the circumstances I'd say.

Though I think you can get a good idea by asking yourself questions like "what things of my grandfather's am I interested in?" and "what kinds of things of their grandfathers are people often interested in?"

Also, someone's always interested in genealogy. So I bet a short bio with a good photo, spread around in a few physical copies, will probably be preserved for quite some time.