Have you thought about using that "global menu" thing? I know nothing about the subject, but the latest move by Ubuntu to include that "searchable menus" thing only works for "the HUD from any standard Ubuntu app that supports the global menu". I Is there some sort of standard out there that defined this behavior? If so, I think it would be worth looking at possibly integrating it with GNUstep.
As I said, forgive me if this sounds stupid, I know nothing about any of this stuff. I just read the blog at (
http://www.markshuttleworth.com/archives/939) and thought that we should be able to make full use of that stuff.
Stef