The "Content Copy" module is a great little module that ships with CCK and provides a handy capability that not everyone is familiar with.
Most developers build a site on the local machine and then upload everything to the live server when they're ready. What happens when they want to add a new content type to the live server though?
A quick and easy way of doing it is with the Content Copy module. Once enabled, it provides an "Export" tab on the admin/content/types page and allows the site admin to export the content type definition as plain text.
The module also provides an "Import" tab on the admin/content/types page that accepts these plain text content type definitions. Simply "export" your new content type from your local machine, then copy and paste the definition to the import page of your live server.