I don't care if you hate their music or if their treadmill video provided fodder for the longest running joke to ever disturb your office milieu. They're still coming out with the best music videos.

I had to find out if it was really done in one shot. Syyn Labs claims it was. I found this on their site:

"When the rock band OK Go, famous for their viral videos including the spectacular and award winning "treadmills video", wanted to feature a 4-minute long Rube Goldberg Machine in an upcoming video, they tapped Syyn Labs to build it. The requirements were that it had to be interesting, not "overbuilt" or too technology-heavy, and easy to follow. The machine also had to be built on a shoestring budget, synchronize with beats and lyrics in the music and end on time over a 3.5 minute song, play a part of the song, and be filmed in one shot. To make things more challenging still, the space chosen was divided into two floors and the machine would use both."

Check out the making-of series on youtube:

AND if you haven't seen it: