For May, Harry's picks include the following:

Accumulative Distance Calculator — Alan Thompson — This routine reports the total distance between any number of chosen points. It works similarly to the built-in Dist command, except that with this routine, you can start a new set of points and the total keeps running.
    
Change Entity Colors — Tommy Shumpert — A unique routine that defines functions for the numbers 1–255 for the purpose of changing the color of selected entities.

Rotate Objects Quickly — Sam Lucido — Quick Rotate is a collection of four separate, but similar functions that allow you to quickly rotate objects 1, 90, or 180 degrees.

Killworm — Mehrdad Ahankhah — Some readers may be aware of an AutoCAD-specific virus that uses AutoLISP spread itself and cause problems. This tip offers a LISP routine to help detect and remove this virus.

Block and Attribute Tools — Robert L. Zipprich — After you load this LISP file, there are three functions in this routine: Xtract creates two files, both with the same name as the block; XtractT searches the Block table for attributes; and XtrtBlk creates a single Tab-formatted file with the attribute values of the selected block.

Polyline Outline — Alan Thompson — Draw the outline of an LW polyline —  linear or closed polylines, with or without arcs.