Two guys calling themselves the "Darda Brothers" created this outrageously twisted and seemingly endless toy car track using a little ingenuity, some clever editing, and miniature cars capable of going a scale top-speed of 600 mph. Ooh, and they jump!
The tiny Darda Cars are called the "fastest in the world" thanks to their powerful wind-up motors. These two manage to take the cars and stretch them into a trip around the world (or at least their house). Even if some of the clips are spliced together, each individual track is sort of amazing.
It looks like the most elaborate slot car track's got some competition.
(Hat tip to Sarcasmo!)