Yes, you’re more than welcome to the code: I’ll sort you out with it when you get around to visiting Aber; or if you get can JTA to pass me your e-mail address, I’ll send it to you.

It’s quite simple, and will integrate seamlessly with WordPress (might require a little re-coding to work with something else, but that’s not so hard). All of the questions, their right answers, and the plausible wrong answers are stored in a text file, which is all you’re likely to need to edit.