I selected this stitch because I already knew how to do it - I used it for the hem on this acorn tea towel:
So here is my example of the beautiful and useful running stitch. The basic running stitch is shown on the far right. But according to the 100 Stitches book, the running stitch can be used as a decorative border when you add another thread with a contrasting color. The middle stitching shows the running stitch "whipped" and the row of stitching on the far left shows the running stitch "laced".
These two decorative additions were fun to do and mine look just like the instruction pictures in the book :) The running stitch is #4 and is in the flat stitches section of 100 Stitches.