I am the proud owner of a stack of scavenged hard drives. I hoped to find really fast, torqueless motors inside. But instead I found myself a project for my new found 555 knowledge.
The logic chip 74164 is a "Serial In Parallel Out bit shift register" (datasheet). S1 acts as a reset button. S2 is the little white wire in the video that "boots" the sequence. Once one serial pulse makes it into the 74164, the system will maintain the sequence. When the pulse reaches the third output (red), diode D1 feeds it back to the first (green).
The motor driver is the well known L293D.
The video lasts as long as 10 minutes. Oh, and you'd better take your sea sickness medicine!