Keyword Assistant (KA) for iPhoto received a 9/10 MacOSXHints rating back in August 2004 as a Pick of the Week. It's been a great productivity enhancer, until iPhoto was updated past 6.0.2 -- Ken Ferry has not updated KA since then, and he designed it to limit KA's features when an iPhoto version beyond 6.0.2 was installed.
This was terrible for me, since I depended so much on KA -- I emailed Ken several times to no avail -- and then browsing VersionTracker's comments one day, I noticed this suggestion by editcandy: