Spire DigiPanel Multifunction Panel
 

From the list of features it is clear that despite the DigiPanel featuring only one knob on the front panel, it is capable of monitoring three temperatures and monitoring/controlling three cooling fans. The knob doubles as a button, and tapping it allows the user to cycle the display between fans, eliminating extra buttons and saving a good deal of space in the process.

URL: http://www.bigbruin.com/reviews05/digipanel?file=1