This is very much a "niche" hint, but hopefully someone out there will find it useful. There are a few instances where you might want to use a laptop with its built-in LCD completely removed, using an external display instead. A couple I can think of are if you've broken the built-in screen somehow and don't want/can't afford to replace it, or have done what I did recently -- upgraded to a new laptop, but kept the old one to use as a server, and removed the old latop's LCD and sold it.
The problem is that even with the LCD removed, the motherboard still thinks that it is there. This means that you could run into a situation where the LCD is set as the main screen (with the menu-bar), and the external screen is set as a secondary display. Getting the menu-bar onto the external display using the GUI in this situation is pretty much impossible.
Here's what you need to do in order to guarantee that the external display will have the menu-bar:
do shell script "/cscreen -d 16 -x 800 -y 600 -s a"
set CurrentMode to ""
try
set CurrentMode to (do shell script ¬
"/cscreen -l | grep \" 1 16 800 600 0\"")
end try
if length of CurrentMode > 0 then ¬
do shell script "/cscreen -s 2 -p"
The first line sets the display properties for both displays, in this case to 16-bit colour depth, with 800x600 resolution. The line inside the try statement checks to see if the LCD (which cscreen reports as having a refresh rate of 0) is set as the main screen (the main screen is listed first by cscreen when listing the current display settings). If it is, the next line sets the external display to have the menu bar, and thereby become the main screen.Mac OS X Hints
http://hints.macworld.com/article.php?story=20060808051946975