I made this sauce the other day and thought I might share it. I buy chile pequins in any store out here. If you're not out west you might have to order them online. It is a hot chile!
(http://i1183.photobucket.com/albums/x465/SiFumar/2011-05-04_13-50-55_721.jpg)
I use the whole bag (1/4 oz) put in blender and blend for a bit, add 1 clove garlic(mince first), pinch of oregano, 8oz can tomato sauce and splash of water. Blend until well mixed. Salt/pepper to taste. The longer it sets the hotter it gets.