I have a fascination with time-lapse photography. One of my favorite parts of "Extreme Makeover, Home Edition" is when they have that one shot of the house being built - In a matter of seconds.
Awhile back I got the k'nex "Serpent's Spiral" for my son. As we started building it, I realized it would be a pretty good subject for a time-lapse movie. So, after 3 hours of building, I compressed the video down to around a minute. Not quite "Extreme Makeover" cool, but still kinda cool.