1) Decentralized Lotto System.
I'm surprised no one else has come up with this feature actually, nor has anyone so much as thought about this feature. I won't post the extract from the whitepaper becuase it's quite long, but I'll post the diagram.
It's probably because it's the silliest thing imaginable to add to a cryptocurrency protocol. But RealSolid actually was going to use a similar gambling lottery as some kind of basis for new money creation, though I don't believe it ever went anywhere.