You’ve seen the extreme 1000fps slow-motion effects and wondered how to do that with your DSLR, which typically max out at about 60fps [to maintain image quality]. Now, a software-based application called Twixtor (from ReVision Effects) allows you to slow down (or speed up) your movie footage as though your digital camera were capable of it.
From keaper.
Here’s another one from ibo456:
And here’s the tutorial from ReVision Effects on how to use Twixtor to achieve the effect: