[futuremint]

The awesome part about it is that your database can be very easily replicated "to the cloud" for backup/sharing purposes.

This is an attractive feature of CouchDB that I'm considering for a web application too.

[tlrobinson]

Is it possible to replicate a users' local database into a shared "cloud" database (many-to-one) or does the "cloud" have to have one database per user (one-to-one)

[mey]

CouchDB's current built in replication doesn't have the concept of sharing partial data yet. It currently push/pulls everything in a single Database. Conversely it's also a trivial thing to create a new database, so one database per user would certainly be possible. Also as the project develops that is functionality that is intended to be there.