How do I get a Mac-like Gnome panel/menu bar (which changes accordingly to the active window).
Solution 1:
Can you provide more information? Unity already comes with a global menu. But if you use GNOME2 or GNOME3 you can use the globalmenu package. You can find more information here:
http://code.google.com/p/gnome2-globalmenu/
And install instructions over here:
http://code.google.com/p/gnome2-globalmenu/wiki/Installation
This adds the same global menu as in Unity.