I've seen that and the reversespeech.com thing ages ago.
I did a little research some time back then, it appears that the Pink Floyd one was deliberate (after all that, you can hear him say "Roger, Caroline's on the phone!") - that one had me freaked out for AGES, I altered the route I walk the dog at night just so I could stay in the better street lighting, I was that scared. It's true.
I'm a massive
ELO fan, how did I miss that one? (I've never actually heard Fire on High, but I still should have heard about it).
I think it's a bit lame that they've found references to Satan in everything, though - a lot of it sounds like complete rubbish until you've had the other person's interpretation forced upon you. Simon Singh brought this up at the Edinburgh Book Festival a couple of years ago, he mentioned about how you'd never notice unless somebody basically spelled it out to you.
On a side note, when I watched Jingle Bells backwards (a few months ago now), it was 2am and I had headphones on. I jumped less than I thought I would, actually.