History of gender (particularly dissident sexualities)
Modern history of the United States of America
History of travel and tourism
Books
(Co-Author with Christopher Saunders), A Dictionary of South African History (Cape Town : David Philip, 2nd ed. 2001); also published as Historical Dictionary of South Africa (Maryland and London: Scarecrow Press, 2000)
Journal articles
‘Discovering Homosexuality in Colonial South Africa: The Case of Bishop Twells’, South African Historical Journal, 36, 1997, pp.48-67.
(with FA Mouton)`A Volksvreemde Historian: JAI Agar-Hamilton and the Production of History in an Alien Environment´, South African Historical Journal, 44, 2001, pp.72-98.
‘Viewing the Past: African History on Film (review article)’, African Historical Review, 42 (1), 2010, pp.113-121.