Userati is an interesting visualization of whose who in the usability world. It uses the number of mentions that Google returns for each person’s name for both Web pages and Newsgroups. I am not sure that this is a comprehensive listing of people, it would be great to integrate the ranking system using publications and references from papers (possibly scraped out of Gary Perlman’s HCI Bibliography, oh if it only had a SOAP or REST interface). It looks like other have their doubts about how the ranking and classification is being done.