Hah, I just thought of a legit use for OMG BLOCKCHAIN.
I've idly wanted some sort of public timestamp assertion server for a while. Like https://tools.ietf.org/html/rfc3161 ... except I'd rather not rely on a trusted third party that might decide to just shut down at some point.
Piggy-backing on a Bitcoin-like blockchain (even Bitcoin itself) seems like a good solution.
I know Bitcoin transactions can carry comments, need to read up on whether they are covered by the transaction/block signature.
@meredith_matthews Smart contracts are much, much broader. But I'm sure Ethereum can do this!
I just want a SHA256 hash timestamped in a way that is really hard to forge, and very likely to remain available long enough to satisfy legal accounting integrity requirements.