I finally got around to trying this while waiting for pizza at a friend's birthday dinner.
Anyhow, I made a simple wrapper script, which essentially calls the gconf commands to enable vibra, runs the command passed to it, and then switches off vibra similarly. I then edited the .desktop files for ATI85 and Free42 so that the Exec lines ran the wrapper (placed in /usr/bin with appropriate permissions) with the original command line (quoted if necessary) as the first argument. However, it does not work properly, for some reason. If I launch it from the menu (Catorize), it will run the application, but vibration feedback will not be enabled; if I run the identical command as the Exec line manually from the shell, it works perfectly.
I can post the exact code here a bit later if needed, but the script is trivial. I was curious if Catorize or the .desktop tools are doing some voodoo in the background that I'm not aware of. Specifically, does the Exec command get executed in the same environment, and as the same user, as when I run it manually from X-Terminal/Ash? Assuming that the .desktop file is being parsed and handled as it should be, then the gconf commands should be executed. If that is the case, then I'm not entirely sure why they are ineffective.
Any ideas?