> The "search" tool is a reasonable solution for "Open" (and the Win7 one
> works remarkably well---in Gnome the command line is quicker: e.g., evince
> "`locate myfile.pdf`").
"locate" is not a search tool in any useful or modern sense of the term. GNOME provides Tracker which indexes document *content* and is quite a good search tool.
I agree that search is generally a good *replacement* for file/folder so long as there is some way to *easily* attribute meta-data / categories to documents. But that's why I same most of my documents on a groupware server.