Being asked for an example of what the Cron Demo plugin possibly could do, I put an example here:
http://wordpress.designpraxis.at/2007/08/13/playing-with-the-cron-demo/
this example shows how admins could send themselves a database backup dump on a regular basis.
The Cron Demo plugin page itself reside here:
http://wordpress.designpraxis.at/plugins/cron-demo/