My PhpBB extension for image quizzes is coming along quite nicely. 18 hours, 657 lines of PHP and 250 lines of HTML later users are now able to create quizzes and take quizzes. Most headaches I had were session handling, I couldn't figure out how to do it properly with the session handling build into PHP, so I resorted to just passing stuff around in very non-SEOed (lately the word SEO makes me cringe) obnoxiously long URLs.
If I had tried to do everything perfectly then I would have never finished, I think it's important to get a first version out before polishing it too much, see what the users do and then improve on it. Obviously it should mostly work, and it does. Currently it's just in Finnish and I enabled it just on one forum to have a limited test. I hope that people will like it and that it would cause people to spend more time on the forum (which I'm not sure Google Analytics knows how to measure), maybe even get some new visitors that come just to take the quizzes.
One benefit I didn't anticipate from integrating with PhpBB was that it's possible to know who the people taking the quizzes are, so I can construct a scoreboard for them. People love scoreboards, it makes them want to improve their score over and over in order to not look bad. My plan now is to see the effect the quizzes have, polish the code a bit, then create a new PhpBB installation (actually all my installations are virtual, not actually separate instances of the software, using a mod I made) which is focused just on image quizzes and redirect my existing quizzes there.
I love the feeling of publishing stuff on the web, not knowing at all if it might be popular or not.