If the settings don't need to be changed very often, but need to be very accessible when they need to be, is there any reason for putting them at the top instead of the bottom of the screen (or vice versa)? It would appear that there is also some differences between putting them on the left or right side of the screen, and also whether it is a web application or standard desktop application.
In the case of a desktop application which settings that are not used often, is there any argument against putting it on the bottom left so it is not out of the way, and use an icon so that it doesn't stick out or is hard to find?