comsLayerIt

comsLayerIt! is an Autodesk AutoCAD plug-in that allows you to dispatch new entities to specific layers automatically based on their type.

The plugin is really easy to use; you just need to open the options form and define which layer should get a newly inserted entity. The settings are user-based, so you have to do this only once and it will work on every drawing you'll work on. There are six entity categories recognized: dimensions (linear, aligned, radius, diameter and angle dimensions), hatches, viewports, texts (MText and single line), leaders (MLeaders and simple leaders), and tables.