I just came across Filecoin on their Github readme FAQ and it sounds like a great idea to me:

"What is the relation to Filecoin?

Filecoin is the sister protocol of IPFS. While neither protocol depends on each other, they are perfectly complementary. IPFS handles high performance distribution of objects; Filecoin handles incentivizing the world to backup/seed objects."

Cryptocurrency backed by real, useful, and valuable commodities (storage and bandwidth).