Digi-Block, LLC
The path to number sense begins with a little green block! Come See the Math!
http://www.digi-block.com/

Omni Block
Insulated concrete block, technical and installation guides, gallery and distributors list.
http://www.omniblock.com

Blockalert
A window into spam activity based on IP block hierarchy.
http://www.blockalert.com/

Defco
Manufacturers of the Blockmaker mobile block-making machine. Includes cost comparison with standard block construction and adobe building codes.
http://www.defcoinc.com/

Concrete Block Association (CBA)
The Concrete Block Association. Provides information on Aggregate Blocks, Concrete Blocks, Part E, Part L, Part J and Building Regulations
http://www.cba-blocks.org.uk/

Earthuprising Adobe Block & Machine Co.
Manufacturer of portable, diesel powered adobe block machines. Site in English and Spanish.
http://www.earthuprising.com/

Seves Glassblock
International manufacturers of glass blocks in various designs, colors and finishes for interior and exterior walls, windows, floors and showers, commercial and residential. Glass bricks.
http://www.sevesglassblock.com

Writer’s Block Consultant
Rose Fichera McAloon Ph.D.: Writers' Block in New York City - Writing consultant specializing in helping individuals overcome writer's block.Dissertators, academics and professional writers have benefited from my unique method. Using both a psychodynamic and hands-on, directive approach, you will be helped to face the terror of the blank page, identify emotional blocks to writing, set reasonable goals, and stop self-sabotaging behaviors. Group work and individual sessions available in Manhattan and Vermont, and by telephone.
http://www.writersblocknyc.com/

Serpent Block Cipher Homepage
Describes the 128-bit block cipher designed to replace DES. It was a finalist in the AES competition.
http://www.cl.cam.ac.uk/~rja14/serpent.html

Block and Tackle
A fascinating article that describes how a block and tackle (as well as levers and gears) works!
http://www.howstuffworks.com/pulley.htm