I got a fine and dandy mini DisplayPort to VGA adapter for my MacBook Pro - I hooked up an external Dell monitor and it works well in landscape.
Any tips on how to make the display on external monitor in portrait mode?
This question came from our site for professional and enthusiast programmers.
The option should be visible by default for an external monitor, but I assume since you're asking this question that it is not.
There's a little-known trick that works for the internal LCD on MacBooks; I suggest trying that: