It took me a while just to figure how to get the script menu to appear at all, to begin with. Looks like all you have to do is go in your /Applications/AppleScript folder and run the small Install Script Menu program. This will get the AppleScript icon to show up in the right part of the task bar, the part that's governed by the system.

Then, you have to create a folder by the name of the application you want to make your script available to within ~/Library/Scripts/Applications. So I created the ~/Library/Scripts/Applications/SubEthaEdit folder. I then opened Script Editor to get the script started. Here it is:

set currentApp to (path to frontmost application as Unicode text)
tell application currentApp
  set screenY to item 2 of screen size of item 1 of (screen list starting with main screen)
  set allWindows to (every window where visible is true)
  set n to count of allWindows
  if (n > 0) then
    repeat with i from n to 1 by -1
      tell window i
	set {x1, y1, x2, y2} to (get bounds)
	set w to x2 - x1
	set h to y2 - y1
	set x to 10
	set y to (screenY - h) - 30
	set bounds to {x, y, w + x, h + y}
      end tell
    end repeat
  end if
end tell

You'll also need the latest version of Jon Pugh's Commands X extension library. This library provides a way to access screen size and depth, and other nice things about your system. I think you'll also need to compile it if you want it to run from the task bar menu.

This is my first script, so I'm pretty sure it can be made better, but at least "it just works"!