gjhiggins, I saw you were helping gapcoin and I just went to research the old datacoin that was one of the coolest old coins that might have been dead and saw a repository that I guess is yours.
My perspective is oblique to say the least. I have a notion to use the OP_RETURN data to carry a URI reference to the signature hash of an RDF subgraph containing metadata and content (hosted on an external, collectively-maintained RDF graph, i.e. a public resource, publicly curated). The signed RDF subgraph can represent anything that RDF is capable of formally modelling. The signature hash of the subgraph is inscribed on the blockchain, keeping everything honest. HD sub-addresses can be used to publish and reliably identify pseudonyms of posters (communicated by side-channel, another role for the communally-hosted RDF service), e.g. publish a FOAF file to the graph, publish the hash signature to the blockchain, an app could retrieve and display the published FOAF data of the addressowner-as-publisher (still optionally pseudonymous), along with the (hash signatures of RDF subgraphs) of other OP_RETURN txs associated with that address, ultimately resolving to, e.g. metadata for a series of blog posts - title, date, author's pseudonym, thumbnail, summary etc. etc.
I had an initial pass (following the
web2web example) using a torrenthash inscribed on the Slimcoin blockchain but ran into practical difficulties getting the torrent content hosted anywhere other than a m/c under my control. And I discovered that torrenthash metadata is confined to file chunk size and hash, there's no user-oriented metadata at all. Hence the RDF graph - for metadata.
(Pilot standalone blog post / torrent content: A different perspective on cryptocurrency, published as an HTTPS resource pro tem - in due course the tabs will be populated by metadata retrieved from OP_RETURN data pointers to RDF subgraphs)I'm in the throes of building out the service into an easily-deployable hosted web app - to which I've given the label, ACME (A Cryptocurrency Metadata Explorer).
ACME could well work for Datacoin - whilst the DTC blockchain can store binary content, unfortunately - like torrenthash - there's no metadata to inform users of the contents of a blockchain-stored blob. So, it looks like Datacoin could well be languishing for want of metadata that reliably and accurately describes the content of what's stored (and therefore what risks attend the content).
As for Gapcoin, well BTCFX browbeat me into it - I reckon he's prolly a headmaster IRL
No, seriously the prime gap work is interesting and as a 0.9 Core clone, it handles OP_RETURN tx as standard, so could pretty much immediately benefit from an ACME metadata publishing service - which could easily be adapted to publishing more detail about the approach, the overall effort and its current state.
If you like, I'm looking to the future, to when people start casting around for an alternative to having to store their published social network content on FB et al. and trying to work out a reliable and useful alternative approach to (what are fast becoming user-hostile) corporate-provided solutions.
Cheers
Graham