Backup and Restore of PostgreSQL

Hi All,

I have a java web server (Tomcat) running a web application that uses PostgreSQL for all
of the data. All of the management of the application is done through the web application
and I would like to provide a backup and restore option for the user. Backup would
somehow get all of the data/schema (maybe not schema) from the DB and zip it and send it
to the customer through the web-app to allow them to save the backup on their local
machine. They could then select this backup file to restore the DB to the state that it
was when the backup was taken.

The backing up and restoring of the system is restricted to administrators of the
web-application (most likely only one person). Backup's would probably be done on a daily
basis with restores only needed upon FUBAR.

What would be the best way of handling this?
Platform is most likely windows, but I would like a system that would work cross platform,
as that is why the whole system uses Java and PostgreSQL as these are available for
Win/Linux/OSX which are the most common desktop OSs.

Ideas, comments or pointers most welcome.

Thanks,
Tim