Typically AutoCAD's Burst command is used to explode blocks with attributes, converting the attributes to text. But if you explode a block where objects inside the block are set to layer 0, the items on layer 0 will inherit the layer of the block once burst.
Drawing objects on layer 0 inside blocks is a good idea if you want the layer properties of the block itself to control the layers nested inside the block. The Burst command is therefore a WYSIWYG block exploder — what you see on screen before the burst will equal what you see afterwards.
Notes from Cadalyst tip reviewer R.K. McSwain: A very nice tip. How many of you know about the Burst command? Any how many of those knew about this part of it? Thanks Matt!