Hey Ed,

Are you thinking of something like this?
http://billwebber.galootcentral.com/smoke.JPG

This was made 30 - 40 years ago.  They were called variously smoke 
grinders, BS machines, or do nothings.  Perhaps round tuits as you suggest.

As for what will I use my ellipsograph on, I'll likely use it as a 
coffee table decoration.  I think drawing an ellipse with a couple nails 
and a piece of string is much easier than setting up the fancy machine.

Bill W.
Nottingham, PA
Woodworkers visit me at http://billwebber.galootcentral.com/