Hi, I have a working prototype of a informal ether/local_currency(AUD) market here
The contracts are on the rinkeby testnet and seem to be working correctly. Please try to break the app and give feedback. A base contract 'Orders' generates new sell and buy order contracts and records contract addresses. To buy or sell to a contract click on the table row (each representing a contract) to bring up fields that interact with the contract whether as 'owner' or responding party. The app README at my github gives a longer explanation.
What I know is still not working: sorting tables, select dropdown values, whisper for communication between parties (not started).