If one endpoint e.g. adds a column to a spreadsheet or a database, automatically add that column / field to other endpoints that support it.

Allow FrontlineSMS users to synchronize a local Excel spreadsheet, MS Access database, MySQL database, or KML file with another FrontlineSMS user via SMS if disconnected or over an internet server if connected

Provide a simple how-to of creating an adapter for some easy storage, including building the adapter and a simle UI to sync it via HTTP

A user was suggesting sync of large files could be handled more efficiently. Currently mesh4x syncs files and images but its implementation isn't the best for items over 300k.
We can make things efficient by having an out-of-band approach like RSync as a transport for data once the basic mesh versioning protocol determines 'which way' items should move.

Give users a way to 'test' if the other side is ready to sync.

Also show basic statistics like messages sent and received, elapsed times, number of deletes, updates, and additions coming and going, etc, (keep the raw log only where developers can see it)

If a mesh4x client is in the same subnet as a mexh4x server or another mexh4x client, automatically detect it and (optionally) trigger synchornizations.
Folks have suggested to use Zeroconf, DNS-SD or UPnP for this so we'd need to research these techs.

[More an exploratory request]
Hibernate doesn't seem have an out of box sqlite adapter, though NHibernate has some sort of support via ADO.net. Is there a lightweight adapter that doesn't require .NET?

With the portable method in which the sqlite db files are produced, it would be a powerful addition to Mesh4x to have a more direct adapter that can synchronize from these files to arbitrary other adapters or other sqlite dbs. We're thinking of an integration of mesh4x and something like Google Gears for portable off-line capable webapps is an intriguing proposition.

Allow a user to browse the incoming changes before 'accepting' them to his own database.
For example, see which items would be deleted, what edits and what new records are coming in.

It is still possible to run Excel (using Wine), on ubuntu, but could the Mesh4x solution rather work with e.g. OpenOffice or Gnumeric?

MS Access has a place to set the Label, lookup values and other metadata for fields of a table. When extracting a schema from MSAccess, this information could be extracted too and used down the read e.g. to generate more friendly XForms

Sync-to-server: A user synchronizes and enters an email adress - the email is received automatically by the sync server and changes are incorprorated (will require some type of signature for offline authentication of the changes)

Peer-to-Peer - User syncs with another user by specifying their email in the app or attaching a sync file with a specil extension. The receiver opens the attachment and it gets merged in.