Manage Outage Notifications?

["Shawn L" <shawnl () up net>]

What are people using to manage / send their outage notifications?  We're currently using a mostly manual process to 
identify customers that need to be aware of an outage and send out e-mail at $dayjob.  Looking for a way to automate it 
more.  I'd prefer something open source, but that's not a requirement.
 
Thanks