Liz Strauss has a very good post on increasing your visibility in the blogosphere.

Like retailers, bloggers benefit from and should seek visibility. Obviously, this assumes you have the goods to sell, and no one should open their store or blog before it’s customer-ready. But once the doors are open, visibility is the key to traffic.
I would add one more item to Liz’s list. Be visible on your own blog.
One person simply cannot create enough content to create any sort of community vibe. You need other people, with other perspectives, to help. And the way to do that it to engage people in the Comments to your posts. This is easy to overlook, and I have done so myself more often than I like to admit. The way to build a true community is to create a site where every post (or at least as many as possible) operates like a little message board where people can discuss the topic at hand.
You also have to respect the visibility of others. If someone increases your visibility by linking to you, or commenting frequently or your posts, return the favor. Some folks try to capture the market on conversation, but the better approach is to treat your corner of the blogosphere as a virtual pub crawl, where you move from one interesting place to another.
Blogs or pubs- it’s more fun with a good crowd.