According to the project (http://code.google.com/p/gnome2-globalmenu/):
"There are several advantages by adopting a shared global menu bar in Gnome (thanks Matthew for organizing these):
- It works better with narrow windows, because the width of the menus isn't limited to the width of the window. (This is a problem for Gimp and Inkscape especially.)
- It's less confusing -- when two menu bars are visible on-screen at once, sometimes people choose the wrong one.
- Global Menu is the first step to move toward a Document Centric Desktop Environment which is, according to us, a long-term trend."
To install: https://wiki.ubuntu.com/DesktopExperienceTeam/ApplicationMenu
This is my Gedit screenshot:
