Multiple exposures while zooming? (Different zoom lengths for each exposure). I haven't really done much investigation into this feature, but my camera will take 9 multiple exposures (in one "frame") and balance it out. In theory I'd get, for example, a runner in nine different positions on the track or (more dynamically) a chance to get something like a triple jumper in half a dozen places on the run in, hop, skip, jump, land.
PSE6 on WinXP, Pentax K10d...... and now a Canon G10.