Last week I was sent a Shape File which defined the outline of a block.
I was asked if I could provide the coordinates of the corner points.
Whilst there are some obscure ways to do this, it is difficult without a full blown GIS application.
As the question seems to be a fairly common one, I wrote ShapeReader to extract coordinates and various other information from Shape Files.
More information here:
http://seismatters.com/ShapeReader.html