Melinda Rose Goodin keeps track of sales announcements in Locus. She conscientiously fills out an Excel spreadsheet with who sold what to whom, via which agent.
Locus spreadsheet: July 2004 to May 2005 (updated 17th May 2005)
Locus, for those who are unfamiliar with the magazine, “focuses on news of the Science Fiction publishing field and coverage of new science fiction books and magazines.” If that’s your playground, Goodin’s spreadsheet is a trove of agent-related information.