This tip is from Mitch Thaxter, who has added functionality to an existing LISP routine by William J. Blackmon. The end result is a LISP routine that creates more than 20 useful AutoCAD commands for 3D navigation and UCS (user coordinate system) control. Before you load the routine, open it up and print out the header, which describes all of the commands this code creates. Each command defined in this routine is executed with a two-letter or two-number shortcut, meaning this tip is especially useful for keyboard users. Mitch and William do a great job explaining what each function does, so there is no need to repeat each definition here. When you are ready, load the LISP routine and give these functions a try. Nice job, gentlemen.