When you're editing a node do you or your editors ever fill in that field at the bottom of the page where it says "Log message"? If not, this module will let you remove it from the page so nobody has to look at it. It will also allow you to remove the entire "revision information" fieldset and everything inside it. The default settings will still apply.
The module will let you choose who sees the fields and where they see them based on role and content type.
The module is in use here: www.turkeyclubsandwich.com