In ufology, many old-school researchers and enthusiasts argue that the internet killed the UFO group and flying saucer club. One didn't need to meet physically anymore to go UFO hunting. The ghost groups show this to be very wrong. They actively go a-hunting, photographing orbs, recording cold spots and EVP (Electronic Voice Phenomena). The active element of creeping around in a cemetery or abandoned building has it's own appeal, whereas UFOs are nearly always cited by people who don't expect them. Also, UFOs are political, perhaps too political for many in the very polarized past five years. Interest in UFOs almost inevitably leads into some element of conspiracy theory, and one of the most recent innovations in ufology is the explicitly activist expolitics. Most ghost stories, on the other hand, often feel safe enough for the pages of Reader's Digest.
Skeptical Inquirer Studies the Ghost Hunters: Biased, but well worth reading
Psychic detective investigates one of the worst fires in American History, the Iroquois Theater in Chicago
Chicago Cop Starts Ghost Hunting Firm
Chicago is apparently all the rage with ghost hunters
Where to buy your Ghost Hunting Equipment
Ghosthunter in Action (with Pic)
Ghost Chicks
Ohio Ghost Hunters, and General Discussion of the hobby
Gary Busey: Ghostbuster
Museum of the Mysteries
Reporter Goes Ghost Hunting
Extensive Article on the Subject in Oregon
The effect of hauntings on Real Estate prices
A Philadelphia mix of the haunted spots and Ghost Hunter article