I store meeting notes in sharepoint. The meeting notes go to my supervisor. They frequently get the email as soon as I create the meeting notes, despite the fact that I have not checked-in the initial notes.
It'd be helpful to have a SharePoint trigger that triggers when File is Checked In. This is difference from the Created or Modified trigger as the Creater/Modified Trigger just fires when a file is created or modified regardless of its check-in status.