[robg adds: I believe this was new in iMovie 6, and yes, it is documented. Search iMovie's help for time lapse, and then click the first link that comes up (Creating a time-lapse effect). However, I wasn't aware of it, and I asked several people about it this morning, and none of them knew about it either, so I felt it worth sharing. You won't see the feature if you don't have your camera plugged in, somewhat obviously -- it works during video import.]

