Cliff Pickover's Internet Encyclopedia of Hoaxes - Discusses a number of scientific and medical hoaxes, including Mary Toft and the Rabbit Babies (about which he authored a book). Includes links and images.
CSICOP:Strange Hoaxes That Endure - Committee for the Scientific Investigation of Claims of the Paranormal: article that discusses 10 hoaxes, including the Roswell Incident, Cottingley Fairies, Amityville Horror, and psychic surgery.
James Randi Educational Foundation - Magician and skeptic James Randi debunks psychics, medical frauds, televangelists, and others. Offers a million dollar reward for proof of occult, psychic or supernatural powers.
Joey Skaggs - Homepage of Joey Skaggs: hoaxer, socio-political satirist, media activist, and culture jammer. Includes an interesting retrospective of his many hoaxes.
Meet Mark Hoffman - A document forger-turned-assassin, Mark Hoffman's knack for "finding" Mormon historical documents and then selling them to the church resulted in scandal and murder.
MIT IHTFP Hack Gallery - The MIT Gallery of Hacks (Interesting Hacks To Fascinate People). Hoaxes and pranks perpetrated at the Massachusetts Institute of Technology.
Museum of Hoaxes - Extensive collection of history's most famous hoaxes and April Fool's pranks. Listed by date and category. Includes bibliographic references.