couchapp for getting things done
All GTD todo managers are overly complex or don't do useful syncing (read: No OTA sync in Things.app). CouchDB is simple and does replication so it seems like a perfect match.
git clone http://github.com/mrtazz/gtd-couch
pip install couchapp
couchapp push $yourdb
Since your tasks may be sensitive data, check out the TODOs to see what is not yet implemented and also read this for a better understanding of the CouchDB security model.
If you want to contribute: