I did some Zentangle-esque quilting as a background fill on the quilt pictured in this post.
http://www.quiltingboard.com/picture...k-t178249.html
Many of the published tangles translate very nicely into quilting and many don't. It is just a style of doodling and FMQ. There are many quilters out there doing similar styles. Some call it doodle quilting and some call it graffiti quilting. If you google images of zentangle quilting, doodle quilting or graffiti quilting you will get loads of examples.