Modeling For 3D Printing - Seperating a multi part mesh

Technically more of a general 3D printing tip, what happens when you download a STL that's actually many pieces, and you only want one or two of them? Instead of printing the whole thing and wasting what you don't need you can separate the mesh into parts very easily using Blender.

http://joes3dworkbench.blogspot.com/
http://learn3dprintingblueprints.com/