Can a Couchbase application work with no network connection (like CouchDB)?
PM from Couchbase here. We've actually been working on an embedded NoSQL database for mobile dubbed "Couchbase Lite" (in parallel with SQL and SQLite) that plays exactly into the scenario you are describing. The idea is to provide your application with a JSON-based database that can:


Opportunistically sync to a backend cluster as needed 
Utilize our built-in P2P support to replicate data between devices without going through a central point
Store data locally in its original JSON format for full-offline access to your data


Some initial reading can be found here (http://www.couchbase.com/mobile#lite) but feel free to get in touch with me if you'd like to discuss more in-depth.