I'm fascinated every time I watch a motion time lapse video. They way they seem to combine slow panning movements with super high speed action all at the same time is just an incredible sight to behold. I'm thinking to fork out and buy one of these rigs for myself to play around with.
Here's a good example of some stunning footage captured with a DSLR mounted on a motion time lapse rig.
And here`s another video showing the rig that's used to make such time lapse videos possible.
This particular type is called the Dynamic Perception Time lapse dolly Stage Zero. The starting price is around $1000US for one of these. Of course on top of that you still need a DSLR, lens, tripod and plenty of time. The latter of which seems to be the hardest to come by recently due to the crazy wedding season.