Toggle Extension Lines — Walt Bedinger — This routine hides extension lines, and it allows you to do this by picking the dimension instead of hunting for the correct item in the Properties palette.

Calculate Total Area, Perimeter, and Length — Andrea Andreetti — Tadd is a LISP routine that will display the total area, perimeter, and length of a selection set of objects. This can be helpful if you want to calculate the total area of multiple closed polylines, for example.

Move Objects to a New Elevation — Theodorus Winata — Moving or copying objects in the z-axis can be tricky if you are not comfortable with the correct Command line syntax, because often you cannot see the result of the move, but this tip makes it easy.

Rotate the UCS and Restore WCS — Alan Praysman — If you generally work in the world coordinate system in AutoCAD, but occasionally need to rotate the UCS about the z-axis, this tip should help you.

Save and Restore Layer States — Raymond Rizkallah — Create temporary layer states using a quick key-in command.

Place Blocks along Multiple Paths — Raymond Rizkallah — This routine calculates a best-fit distance so that the blocks are evenly spaced along the entire path.