A version of carmen modified my Conservation International to include the following changes:
Only matches from the users profile (other resolvers will likely not work)
Only returns the country for a toponym (not the lat/long)
Includes a vastly expanded database with all cities over 20k people, all countries, admin 1 and admin 2 names, as well as extensive alternate spellings and names for a given toponym.
Works with unicode, allowing geocoding user locations that are not ascii.