Masonry

Overview
The Masonry Add-On for Blender, in general, is used to create a "wall" with rows of "blocks". It is easy to create a "castle-like" wall using the Masonry Add-On. It's easy to do a lot of things in Blender - Hopefully this will help you do them quicker/better.

Links

 * Using Auto-Masonry
 * Making a Tower
 * BlenderCookie video