Below are some examples of utilizing the blocks to hold shop made jigs and fixtures.  The upper left photo is a right angle jig.  It will hold two boards at a right angle for assembly.  The upper right photo is a dovetail jig being held in place with the vacuum blocks.  The lower left is a pocket hole jig being anchored by the blocks.  The lower right photo are the blocks holding a straight edge guide and the panel in place to cut dados for a cabinet side.  There are two blocks holding the edge guide and two blocks holding the panel to the workbench.  Uses for the blocks are limited only by your imagination!