Here is a link to over 40 potholder patterns and tutorials-free.
http://tipnut.com/potholder-patterns/
A few shown are considered microwave potholders. Those with a potholder for each hand on the end.
There are also microwave bowl potholders. Here is one link. Google microwave potholders and several come up.
http://www.youtube.com/watch?v=OlN8hXpaUV4