Hand of Evil said:
At one time I heard where some group was going to try and pull sound from pottery and brick, the theory was that sound is imprinted onto items during creation. Never heard any more about it but this make me wonder...
Did you happen to hear this in a Visual Arts class at UCSD, circa 2000? I had a TA bring up this "research", and later admit (in private) he just thought it was a cool idea, and wanted to see if we'd believe him... I haven't ever heard of it existing elsewhere (although the cactus-needle thing is similar, it's not the same, whereas the "imprinted in pottery and brick" thing is exactly what he said...)
Regarding EVP, it's fun and creepy, but I think it's just examples of normal radio interference. We hear it all the time in white noise, it's just that 99 times out of 100, it's something mundane, and we don't notice it... It's only when we hear something creepy that it stands out.
My closest personal experience is kind of funny: I was at a friend's house several years ago, playing Mortal Kombat II... At one point one of us, I don't know, fell off the couch or something, and somehow the controller got jerked out of the machine, which caused the game to crash. It kept on playing the buffered portion of the sound sample -- it was the "Flawless Victory" phrase, in that evil voice, except it was only playing part of it, so it was repeating "Victor" over and over again.
My friend's name was Victor. It happened on Halloween. And we were teenagers to boot

So while it can hardly be called supernatural, it was still superbly creepy.
Anyway, as a plot point, it's a very good one... Hell, if you got some good tech people behind it, it might just justify a LARP.
