easiest way to convert video into a series of still images

This isn't a Jitter specific question, but I find this a good place to ask general AV stuff to a sophisticated audience used to doing odd things with many applications.

I'm wondering what's the easiest way (using any kind of software) to convert a quicktime movie into a batch of jpeg images numbered by frame. In other words, I have a folder with 1.jpg being the first frame, 2.jpg being the second frame, etc. The clips will be quite short, all likely under 10 seconds in length.

Any ideas?

Thanks,
Zach