Does anyone know of a pattern for an adult poncho with "holes" or plackets for arms to come through. Free pattern would be preferable. Thanks. Carol

You probably don't need a special pattern.
Just make a basic poncho or ruana and, starting at the bottom, sew up each side until the opening ("armhole") is the length you want it to be.
This will work much better on a poncho with a straight-across bottom rather than a point.

Like this:
http://www.lionbrand.com//patterns/klsu-poncho.html

And this link has tons of poncho patterns.
http://www.knittingpatterncentral.com/directory/ponchos.php

You could also hunt down an old circular cape pattern, which often have arm openings. There may be one in one of the Elizabeth Zimmerman or Maggie Righetti books.