Using timelapse photography lets you notice things that you might not otherwise; same with slow motion photos.
Casio is blowing us away by showing their new $999 super-high-speed digital camera, the EX-F1. It is capable of the following speeds:
-- 1200fps at 336x96 resolution.
-- 300fps at 640x480 (VGA)
-- 60fps at 6 megapixels (full resolution).
-- 30fps at 1080i in H.264 movie format.
Engaget has photos and video here.