I'm currently using Ubuntu linux. There is a feature avaliable called global-menu, which provides mac-style global menu bar - common menu bar for any application. But I wonder (as I've never used a Mac, though want it so much) what are the main advantages of such an interface? In windows/linux you're working with a "local" menu of an application, but with global you need to drag cursor to the upper side of the desktop. Could someone tell me the answer?
The main advantage of having the menu bar on the top is to provide faster access to the menu options (according to Fitt's law) as you don't need "accurate aim" on the vertical axis to reach it (basically your hand only needs to search horizontally).
You may have used other applications that take advantage of the same concept (once again from Fitt's law). For example with Office 2007, Microsoft decided to use a new "Office" button located on the upper left corner as it has "infinite size" -there is no need to aim on either the vertical or the horizontal axis- (as long as the window is maximized).