I think it was Sharon Pederson, first in her Reversible Quilts book and then in the Sensational Sashiko book, who had a method of using the thicker white thread on top with a thinner thread in the bobbin that matched the background fabric to create a faux Sashiko stitch by machine. It was pretty cool.
Ah, here it is:
http://www.youtube.com/watch?v=MB5fsTvMCA4
It's right after her intro.