I'm one of those folks who believe there's no such thing as psychic powers and that anyone who claims to have them is either deluded or, more likely, an enormous fraud. This also applies to those who claim to be able to communicate with the dead.
One of the biggest frauds was a fellow named Uri Geller who attained some prominence in the seventies claiming to be gifted in psychokinesis, dowsing, and telepathy. His demonstrations were all accomplished with fairly ordinary magic tricks but he still fooled an awful lot of people.
He would have fooled more but for a gent named James Randi, who appeared on TV and wrote a book exposing Geller's chicanery. I've linked to this before but here's a good profile of Randi that ran in The New York Times. I call your attention to this paragraph…
…when Geller was invited to appear on The Tonight Show Starring Johnny Carson, the producers approached Randi, who had been a frequent guest, to help them ensure that Geller could employ no tricks during his appearance. Randi gave Carson's prop men advice on how to prepare for the taping, and the result was a legendary immolation, in which Geller offered up flustered excuses to his host as his abilities failed him again and again.
"I sat there for 22 minutes, humiliated," Geller told me, when I spoke to him in September. "I went back to my hotel, devastated. I was about to pack up the next day and go back to Tel Aviv. I thought, That's it — I'm destroyed." But to Geller's astonishment, he was immediately booked on The Merv Griffin Show. He was on his way to becoming a paranormal superstar. "That Johnny Carson show made Uri Geller," Geller said. To an enthusiastically trusting public, his failure only made his gifts seem more real: If he were performing magic tricks, they would surely work every time.
That episode of The Tonight Show, which originally aired August 1, 1973 is being run this Saturday night on Antenna TV. Geller's segment can be viewed in many corners of the Internet but you might find it interesting to watch the entire show and see it in context.