I've made several denim rag quilts and hope to soon get back to making more. Some of the jeans I used were 20 years old, some were mixed fabric content; all have turned out to serve their purpose ... utility quilt and dog quilts.
Here's a couple of pictures (front and back - no batting) of my favorite one:
[ATTACH=CONFIG]488948[/ATTACH] [ATTACH=CONFIG]488949[/ATTACH]