This would work with 'Unity', but I confirmed it does not work with 'gnome-applet-globalmenu 0.7.10'.
So what does it do? Who needs it? What are the benefits? Is it better to install it through package manager?
For everyone downloading this -- you don't have to. LibreOffice 3.4 includes better integration with GTK+. That also means that LibreOffice 3.4 has Global Menu support built-in.