One powerful feature built into WordPress is it’s ping services capability. Basically, whenever you update your blog with a post, WordPress has the ability to reach out and notify various websites that you’ve added new content to your site. Therefore, you can possibly be listed in various search areas and other locations and gain more traffic passively. It’s really a no-brainer to get this enabled, since it generally doesn’t do anything negative and can only add more traffic to your site. To get more information on a good selection of ping sites check out the Update Services page at the WordPress.org codex.
Oh, one thing I do need to mention, the one negative that can happen after adding services to your list can be that your posts take longer to add to your blog. This is because at the moment you add the post, it sends out the ping–so a delay at any of the servers on your list can slow down the total process of posting. There is a plugin called “No Ping Wait” that’s out there for those of you using WordPress 2.0.x though to help with this. For versions past 2.0.x the delay has been mostly eliminated though, so it shouldn’t be a major issue for those users.