Here is a video I shot and edited for the Mammut testevent 2009:
In iMovie ‘09 you can sync edit points with beats of the music. You have to add the beats yourself. I did this by ’tapping’ (the ’m’ key) along with the beat while playing back the music. Unfortunately, if you don’t ’tap’ slightly before a beat, it actually gets placed slightly after the beat. There is a bit of a delay. In this video it is not too noticeable. (Of course now you’ve read this you do notice it ;-)