I've begun noticing a new Web design trend that I'm calling "the dot-dot-dot thing." Remember when everybody's site background was black? Then when everybody got frames? (Then dumped them.) Next, when you couldn't swing a dead cat without getting stuck in a Flash intro?
Now it's the dot-dot-dot thing to give some structure to a logo or navigation bar, without the harshness of actual ruled lines. Check it out on these three sites, and I'll bet soon you'll start seeing it everywhere.