I got a note from Jeff Kellogg at Pavilion Literary Management recently, noting that he was actively seeking some areas of nonfiction.
The categories are:
Submit your work to him at 660 Massachusetts Ave., #4, Boston, MA 02118, or at firstname.lastname@example.org. See the agency submission guidelines here. Pavilion actually represents a variety of fiction and nonfiction topics, in addition to those above being actively sought.