Original Tip Date: Jun 26, 2013
If you have a large number of blocks and want them to be in a cell library (instead of plainly using the "Attach folder.." in the cell dialog) go through the following steps:
A. Drag in the Blocks as references B. Save as DWG "Ref as Cel" C. Export to Cell Lib
And ... voila ... you got your Cell Library with the cells named as the blocks they originated from.