In the Limelight with Lenny video he made the comment that when shipping a new  library they restrain themselves to prevent alienating customers with fancy or convoluted features. 

I’d like to know what cool, convoluted and useful features people have added to their products and libraries to improve productivity. 

As an example here are some  ideas I’ve seen implemented:

• A scribe text function that converts text to a polyline machine token  for carving text on panels.
  
• Materials associated to their own layer making it easy to isolate each material in the drawing.
  
• Trig functions that provide the angle the saw needs to be set at when doing a secondary compound cut on a table saw.
  

What features have you added? Or would like to add?