I've been practicing "straight" line quilting using my walking foot. I've tried straight lines, zig-zags, decorative stitches, and the ever-elusive wavy line. Even after reading about a billion blog posts about how to do wavy lines, I can't seem to do it. My waves aren't even, and don't look very good. The decorative stitches, however, look pretty cool. I'm especially fond of the greek key pattern (it was Adam's idea to try that one out) and the scalloped line.
It's nice to have more options for quilting, but I probably won't be branching away from straight-line quilting or free-motion quilting any time soon.