I was wondering if there is a practical limit to the number of display lists that OpenGL can handle. And will using a high number of display lists slow down my application ( not counting the number of calls to glCallList ). Thanks for any help.

Eventually you should reach some kind of limit in your hardware even with display lists or any kind of method of rendering polygons and fragments. I mean you could throw a 20 million polygon display list at your videocard and I am sure its going to slow down...