I recently mentioned this forum to a guy at work while we were discussing ghost-hunting and whatnot. As it turns out, he already had experience with this stuff, and had talked to at least three or four mediums over the past year trying to reach the spirit of his mother for help in some family dispute. I won't bother you with the details (because they would bore you, trust me), but in the end all but one of the mediums he talked to were either unsuccessful or obvious charlatans. According to him, the only one that did actually seem to reach his mother (or fake it well enough to be believable) was the one he only interacted with via telephone.
So what made that one medium succeed where the others had failed? Random chance? Do spirits feel more comfortable making contact when only strangers are present?