Noodlesoft released Hazel 3.0.14 to enable you to edit notification options from the file cleanup utility when running in OS X 10.8 Mountain Lion. Accessed via the gear pull-down, you can select Notification Center or Growl (if you have the latter installed) and specify which kinds of notifications should be displayed. (By default, Notification Center gets the nod if both are available.) The update also fixes instances of Hazel not keeping track of Trash if it is empty on startup and more reliably matches patterns with accented characters. Noodlesoft subsequently issued version 3.0.15 to fix a crash in notification options and a disabling of the gear pull-down when notification options are available but no folders are present. ($25 new, free update, 6.2 MB, release notes)
Compare More Easily in Apple Mail
In Apple Mail, if you need to work back and forth between two different views of Mail's mailbox contents, you can do so quite easily. For example, you might want to look at a mailbox holding all filtered-in sales orders from the past week while also looking at a smart mailbox showing unanswered customer questions.
To avoid constantly clicking between mailbox views and losing your context each time, choose File > New Viewer window to get a second window and then arrange each window as desired.