Steve has blogged about commandline notifications and variables. "When enabiling modem paging (or similar) it is often a requirement to pass the user name or phone number of the user being contacted to the application handling the paging operation. In MOM 2005 this was easily done using the $operator$ command line variable. It is still very easy to do in OpsMgr 2007 but the mechanics have changed. "
Last week I also used the Notification Command Channel at a customer for Notification Auditing. The customer wanted to have some proof of the notification being sent. This can be achieved with the creation of a Notification Command Channel. You can use the EventCreate Commandline tool to have the Notification logged in the Application Eventlog.
And the next Commandline Parameters will log the ManagedEntity Full Name in the Description field with EventID 999
/ID 999 /T SUCCESS /D "Notification Audit Event for $Data/Context/DataItem/ManagedEntityFullName$"
This can also be used as a way of testing your notifications. You don't have to wait for any email or SMS to know if the notification works the way you want.