Set Each Layer Current —  Kent Cooper — This AutoLISP routine allows you to interate the layer table in alphabetical order (or in reverse), setting each layer current along the way. Layers that cannot be set current (xref-dependent and frozen layers) will be skipped, but layers that are off can and will be set current.

Standardize When You Save and Close — James Sturgess —  This LISP routine ensures all drawings are saved with all layout tabs and model space zoomed to extents.  It can be easily modified to do anything that needs to be repeated on each layout, such as filling in title blocks or revision blocks.

Export Layer Names — Michael Nelson — This LISP routine is for anyone wishing to export a list of layers from the current drawing to a text file. The author uses it to quickly export layers for later analysis and makes note that you could even have a script run this routine through hundreds of DWGs in a short time.

Control Xref Layer Colors — Matt Sibum — This LISP routine generates a list of xrefs with three options for the colors of the xref layers: Default (keep things as is), Reset (reset colors back to those in the source drawing), or Change (change all layers to a single color). If you are in a floating viewport, you also have the option of making these color changes to just that viewport.