Sometimes, while diagramming in rhino, it helps to easily see to which layer each object belongs. This script simply adds a text dot of 'layer name' at the center of each object, and then groups it with the object.
LabelByLayer.rvb - (change .txt to .rvb)
To start, select the objects to label. For layer names, I've allowed for the removal of prefixes and suffixes ("prefixxxxLayerNamessssufix" to "LayerName"). I've found that to be helpful when dealing with complex files:
Lastly, for rhino5, the script has the option to change text dot sizes:
Note that to undo the effects of the script, you should select the dots (SelDot), delete, and Ungroup the massing.