I think binder clips are one of those underrated items that are super useful, even if you don't use a binder anymore.
Actually, even when I was using a binder in high school, I don't think I was using binder clips.
Now? I use binder clips all the time! They're up there with one of my top items for hacking everyday problems. Need to close a bag of chips? What about keeping a tablecloth from blowing away? Seriously, these little guys pack a mean punch!