We are shooting some fast-action scenes (like race-cars flying past camera) and we want to get that super smooth, slow-motion framing we've been seeing a lot lately (perhaps to even time-remap the action as well---normal speed to slow to normal again. We know how to time-remap already). Are there any demo/instruction or pointer resources to help us know how to achieve this look before we go out and experiment?
We are shooting with a Panasonic HVX-200 in HD mode.
I think a lot depends on just how "smooth" you want smooth to be. As I'm sure you know, slo-Mo is usually accomplished through over-cranking -- running the camera at a faster speed so that when it's played back at normal speed everything goes slower. How much can the Panny 200 over-crank? On our Sony 350 the most we can get is twice normal. You may have to rent (or borrow) one of the higher end Panasonic Varicams to get what you're looking for.
I certainly don't claim to know much about this, but I believe that frame blending in After Effects can also add to the "smoothness" of time-altered footage. Ask on the AE forum where you'll find people who know these things.
There are several high speed camera systems around that will easily give you up to 4,000 fps. However, in our experience in tests done by Michael Brennan (also see http://hd24.com/page8/page38/page38.html) you need to select your shot carefully. Wide shots won't work as well as fast moving close-ups. Also, expect to do some work in post to deal with flickering and grading - but that is not any more difficult than when trying to use HD progressive material for slow-motion.
If you want to do this on a budget, check out industrial camera suppliers. Normally they use high-speed cameras to capture processes such as machinery, vehicle crash tests and shooting guns, that are all too fast to see.
You can't get the ultra clean slow mo you've seen so much lately unless you shoot at higher frames per second with a different camera. That said, I get nice results with drag racing drive bys with fluid motion in avid and just using time remapping in AE.