I'm told that the instructions in the man page for installing XScreenSaver on Gnome 2 systems no longer work on Gnome 3 systems.* Can one of you with access to Gnome 3 please figure out the new way to do this stuff?
I also don't know whether the KDE instructions are still correct, so it would be nice to have an update on that as well.
On another note, if you run Linux in Japanese, and are capable of re-compiling xscreensaver, it would be helpful if you would take a look at this bug and help us figure out what goes wrong when you have non-ASCII characters in your password. Particularly see comment #20 and later.