There's actually a full fledged Twitter clone on Ethereum - http://leeroy.io http://leeroy.io. The difference is that it uses full-fledged contract storage, so

There's actually a full fledged Twitter clone on Ethereum - http://leeroy.io http://leeroy.io. The difference is that it uses full-fledged contract storage, so the cost-per-post is ~10x the gas. My attention has re-oriented towards Whisper instead, which ultimately is the right place for this in the web3 stack.