The way to do this in many cases is to create your own category. I met a fellow once while working in New York City who ran his own show for free on a community television station. Cable as well as community television stations are wonderful mediums to get the word out effectively. This is an area in which you can get a lot of publicity at little or no cost. He also takes calls on the show and has an e-mail format where people can ask questions online and to which he'll answer directly on the air.
Publicity is greatly different than advertising.
There are many different ways to get publicity out there, let alone free publicity. But the idea behind publicity is not to market yourself, or at least not directly. Your goal through publicity is to get yourself known and known as an expert in your field. If you have narrowed your focus to a very specific, highly specialized field, publicity will come easy to you. The media loves to receive information from people who are uniquely qualified in their specialty.