https://i.ytimg.com/vi/YjOSkSQtGOM/hqdefault.jpg
All you wanted to know about Extruding in 2.5 Blender.
Extrude Region
Extrude Individual
Extrude tip for angle extrusions.
Praying Mantis tutorial mentioned in video is here:
http://www.blendercookie.com/2009/08/28/modeling-a-praying-mantis/
Removing doubles
Vertex Edge Face data in interface.
source
Link to this post!