I've drawn up a first draft of the circuit diagram for the CD-ROM spinner control, using the Hall-effect sensors in the brushless DC motor. Here's a small version; follow the link to Flickr for bigger versions:
The three square symbols on the left are the three hall-effect sensors in the motor. Mine were connected in series by the PCB on the motor itself, and I just used two 100 Ohm resistors to send a small current through them. The bigger blobs on the diagram represent connections to the motor, and connections to the Arduino (any three digital inputs will do).
Now, I'd better get on with the photos and the sketch code...