"If Jesus was Jewish, why did he have a Puerto Rican name?" ~Discordian Koan
Discordianism, or Erisianism, I forgot which, is a purposely confusing spiritual path whose devotees are nominally devoted (or at least they say they are) to the worship of Eris, the Greek goddess of Chaos and Discord. If you thought that sentence was confusing, stop reading now. Discordianism is a joke of a religion that started as a joke. Or is it a religion following a joke that began as a religion...? In any case, Erisianism is alive and well, and growing in followers everyday.
It all began when two friends, Malaclypse the Younger and Lord Omar Ravenhurst were drinking coffee at an all night bowling alley. Time froze and they had a vision of Eris, who told them they were free and mentioned the concept of chaos as a constructive force. They developed a holy symbol based on the idea of the balance between chaos and order:

In this image, order is symbolized by the pentagon, while chaos is the Apple of Eris. According to Greek myth, Eris began the Trojan War when she disrupted a wedding on Olympus by rolling an apple into the banquet hall. The apple was inscribed with "to the prettiest one", and so three goddesses went after it, each wanting to for their own. Zeus chose a mortal, Paris, to decide who got the apple, so each of the goddesses bribed him. Paris took Aphrodite's bribe, which was for the most beautiful woman in the world, and he got Helen and screwed over the city of Troy.
Adherents of this non-prophet disorganization treat religion as the joke that it is and do just about everything in mockery. Discordians almost never seem serious about anything. They have one main text, the Principia Discordia, which sets forth the (non-binding) principals behind applying chaos in your life, and a slew of not-main texts, each of which is a collection of pranks, stories, theories, and a bunch of other crap that could be seen as "inspirational" to Erisians.
The major concept of Discordianism is the idea of using constructive chaos to counteract destructive order.

The closest thing Discordians have to worship is spreading chaos in the form is pulling pranks or doing weird and confusing things. Operation ******** is an ongoing prank-pulling spree that anyone can participate in. Discordians seldom pray (note the example of the village in a drought who prays and gets wiped out with a tidal wave), but they contact and talk with Eris through their pineal gland. (Mystics will know that the pineal gland is in your forehead and corresponds with the third eye.)
Discordians also tell jokes of a religious nature. Much of Erisianism pokes fun at conventional religion, while at the same time acting as a vehicle to deliver spiritual knowledge. (Many Discordians will disagree with me, but then again, by nature, there is no right and wrong when it comes to Discordianism.)
I am fully prepared to answer any and all questions on Discordianism, serious or notFnord!
Further Reading:
For the Right-Brained: Wikipedia (Contains boring, straightforward information.)
For the Wrong-Brained: Uncyclopedia (Contains exciting, confusing misinformation!)