Carolyn Howard is a well-known non-fiction writer. She has partnered with another author to do advance marketing for their upcoming book by creating a site for their book proposal here.
It includes their excellent agent query letter here. Their Fiction Marketing site also promotes Carolyn's ebook on making a good first impression. They also include a sample of their blogging chapter, which builds interest for the book, draws visitors to the site, and increases their chances of attracting serious inquiries from agents.
Take a look at it and consider this unusual method of making your work more visible, and showing both your readers and potential agents that you can deliver an unusual approach to marketing today.