The Quadra 840AV surprisingly does not come with a cable for Apple's new AudioVision Monitor. This in itself would be understandable if the monitor came with a working cable, but the cable doesn't plug into any of the 840's ports. Evidently, Apple plans to add the proper port to future 840s, but in the meantime you have to call Apple and order a special cable. Russ Black <firstname.lastname@example.org> posted a note about this on comp.sys.mac.announce and said that Apple charged him for the cable and that their current computerized ordering system didn't even know about it. Apple, you can do better!
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.