Backmasking Icons
Everyone knows that if you play certain Beatle's records backwards you can uncover the conspiracy that Paul McCartney died and was replaced. There are other albums, especially metal albums, that make use of this technique, called Backmasking. In it a sound is placed into the music that means nothing played forwards, but played backwards its intelligible.
In order to find Backmasking, one must either already know to look for it, randomly play everything backwards, or hear something that sounds interesting and essentially just stumble upon it.
In regards to stumbling across almost subliminal messages, I just found a funny one. I use the Famfamfam Silk icon pack a lot. I mean a LOT. Just about any website I set up will use at least a few of them because they're so clean and, well, free! (And since I'm plugging him, I'll point out that these are licensed under the CC Attribution 2.5 license, so if you end up using them, make sure to attribute!)
Browsing through the big ol' image of all icons I came across this:
I've browsed through here may times before, but this time I read that as "drink and drive", and then I just couldn't help but notice the hidden commands.
1) Get a drink.
2) Empty drink.
3) Drive! (and you'll notice later on there's drive_error, and drive_burn... as such I highly do NOT recommend actual drinking and driving).
Hope you get a chuckle out of it as well.
(DISCLAIMER: Neither I, nor Mark James/Famfamfam, would ever encourage any form of dangerous or illegal behavior. Do not drink and drive... period)