Took the audio file Martin created and added it to the video. I removed about 6 seconds in order to make it fit (once again, iMovie '08 disappoints) and re-exported it.

The students building the site dropped by with some fairly straightforward CSS/HTML issues and I helped them with that for a bit.

I now know that although the Flash player does not play any audio files other than mp3, it does play back non-mp3 audio streams embedded in mp4 video files. I know this because iMovie '08 will only encode embedded audio with AAC. The file still plays, though. I spent a good deal of time trying to embed mp3 audio in an mp4 video and had no luck. I did this because the video initially played back without audio - and I assumed that it was due to the only-mp3-audio issue in Flash. It is more likely that it was in fact a cache issue. This of course means that I buggered about with this "issue" for no reason.