Development has slowed to a crawl, but http://datacoin.info is still alive. It focuses on redundancy, as all participants have a full copy of the database, and so data amounts are small (1 datacoin = 20kb). Still, there's a potential use case there for text-only content.
Definitely looking forward to distributed storage apps; other projects in progress include BitCloud, MaidSafe, and Ethereum.
Participating in Datacoin sounds legally dangerous. All a miscreant needs to do is include into its blockchain some files that are illegal to possess, and everyone is potentially in trouble.
Such link could be sent with a bank transfer too - I don't think you could then claim the bank holds and spreads the links to child abuse. Or could you?
That's an interesting scenario, and I don't know how much distinction is made between possession of illegal material and possession of a means of instantly retrieving it.
Datacoin has the storage capacity to include the actual images as part of the blockchain though, not just (probably quite ephemeral) links to such.
