Script to Show/Hide Preview Pane in Mail
Sunday, January 20th, 2008
After switching to mail.app from Thunderbird, the blogger at 48-Hour Days found that that she (or he) couldn’t live without Thunderbird’s F8 keyboard shortcut for showing and hiding the Preview Pane.
As everyone knows, you can show or hide it in Apple Mail by double-clicking the small dot in the separator between the Mail Viewer and the Preview Pane — Apple’s Technote
shows you how.
But if that is not quick enough for you, 48-Hour Days provides an applescript
that will automate the process and which can be bound to a Quicksilver trigger or FastScript’s shortcut.
Only hardcore keyboard fanatics will want to use this, but there are people like that out there, and this post is for them.
Tags: Apple Mail, Apple Mail Tips, applescript, keyboard shortcuts, mail.app, preview pane, thunderbird
Aral Balkan has written a clever applescript that makes it possible for mail.app to reply to multiple emails.
Copy 
John Maisey has updated his AppleScript for deleting duplicates in iCal, so that it works with Leopard.

John Gruber of Daring Fireball fame has written up
As he correctly points out there is no default menu option in Leopard Mail to access this feature. However
Andreas Amann has pushed out two quick updates to his Mail Scripts applescript collection.
Just when I thought I had posted enough for today, Andreas Amann releases a updated, Leopard-friendly version of his most excellent Mail Scripts.