Via the /r/mildlyinteresting* subreddit comes an office-supply creation that puts your cubicle-mate's obnoxiously oversized rubber band ball to shame.
It is decently heavy. I can toss it between my hands with no issue, but my co-worker threw it like 4 feet to me and it hurt to catch.
EDIT: A lot of people have asked for instructions. I'll try and provide some soon. Gimme like a week to figure out how I'm gonna do that. That's definitely something I'll have to put together at home. I ran into several problems while making it that I had to overcome with trial and error so I have lots of suggestions and I'm happy to help others make their own binder clip balls.
It's only a matter of time until someone carries this idea to its logical conclusion and uses some of these:
...to make an even BIGGER binder-clip ball. Assuming, that is, that Lion Extra Large Binder Clips possess the dimensions necessary for spherification; according to Eduardoballestero, he had to look for clips with proportionally wide prongs.