those of you who have been wondering about how to copyright your designs should visit the U.S. copyright office web site.
A copyright once registered, is good for the life of the creater plus 70 years, at that time the item is placed in public domain where it is then accessable to anyone for any use. there is a filing fee, but if you file on line it is less than going through other channels.
the article about copyrights in the Sept/Oct 2010 McCall's quilting is very informative about the rules using a copyrighted item...the copyright office has tutorials about the process of getting the copyright in the first place.