How to share CCK data accross separate Websites.

I am working on a project for an association of institutes. Each institute should have their own website with their own self-administered content. The problem is that some of this content, for example employees, should be aggregated on a separate website that functions as portal for the whole association. What would be the best strategy to handle this. I have considered three possible solutions:
1.- Create a template for CCK that publishes the information in XML and then create a module similar to the RSS reader module that aggregates the information.
2.- Create some kind of hook on the CCK module that updates the information on separate databases.
3.- Have some script, run by a cron job , that regularly synchronizes the tables.
I am new to drupal so I was kind of tending towards solution three, but it would be nice to have some other opinions.
Thanks.