Vision Research, with their Phantom line of high-speed video cameras, has kind of outdone themselves this time with the Phantom v1610. A MILLION FPS!? Imagine what people getting punched in the face would look like slowed down that much!
Truthfully, it probably wouldn't be that awesome. With high speed video, at some point, the law of diminishing returns kicks in. We all like seeing three seconds of jiggling Jell-O stretched out into a 30 second video, but think about it: three seconds of Jell-O shot at 1,000,000 FPS and then played back at a standard rate of 30 FPS would make a video clip that is almost 28 HOURS long. Yeah, no thanks. So what the hell are the practical applications?
The answer: stuff that goes BOOM! Have you ever watched a Mythbusters, and they're blowing something up with C-4, and you just can't wait to see the super slow-motion video shot of it? There's usually a jerky three frames of the explosion itself and the rest is just debris slowly falling. This is because explosives such as C-4 have a detonation velocity of over 8000m per second, which means that most high-speed cameras simply can't catch it. The Phantom v1610 should be able to make it look buttery smooth.
Buuut, it won't. In order to crank the camera up to it's 1,000,000 FPS max, you have to drop the resolution down to 128 x 16, which is only OK if you're looking at your TV through a telescope. The camera has a 16 gigapixel/second limit, so you have to find the balancing point between the resolution you want and the speed you want. You can shoot 1280 x 720 HD at 18,100, which is still extremely fast, and if you are willing to settle for a standard-def shot at 640x480 you can crank it all the way up to 43,400 FPS, which I'm betting would look pretty amazing. There are many more options in between.