Generally, you are thinking about your job search correctly. Having not gotten any results from your efforts so far, you should be asking yourself (and others) what you should be doing differently to meet with more success in your job search. Even so, your question assumes that the hurdle you are encountering has to do with how you are transmitting your interest to the firms. I don't think that's a safe assumption.
Let's talk first about timing. You are looking for something that will start in the Fall of 2010. One of the by-products of the recession has been that law firms are seriously reducing their expectations for how many new associates they are prepared to take on. Though I don't encourage people to spend too much time pouring over all of the bad news coming out of law firms, it is important to know what is going on in the industry. For the last several months, many law firms have been announcing that they are deferring start dates, both for incoming class of 2009 and class of 2010 lawyers. Some law firms have cancelled their summer programs, some of seriously reduced their summer classes. What does this mean for you? It means that there is a great deal of uncertainty about future hiring needs. By applying now for a position that will start in a year, you are essentially asking a law firm the question ''will you need someone with my skill set this time next year?'' In today's economy, the answer is almost certainly ''who knows?''