Blake, a reader from xlr8yourmac, has used a feature of Hardware Monitor's latest version which allows the display of all monitoring information on an external LCD module. He purchased the required equipment, did some simple welding on it and here were his CPU's frequency and temperature displayed on the screen.

Based on an
IO-Warrior 24 Starter Kit USB controler and on a
4 lines LCD display, the whole kit costs less than a hundred euros.
Hardware Monitor support information about that mod.
Blake's personal webpage to see the pictures and the video.