Not really a joke. But it doesnt fit anywhere else. Some of you may find it humorous 
History
Though the origins of L33T are unclear, most sources locate its beginnings during the early 1980’s. L33T was originally used as a way for hackers to discuss techniques and triumphs on bulletin board systems (BBS’s, and later on websites, newsgroups, messageboards, etc.) without being detected (by the law or the public) by keyword searches in search engines. The original form of L33T simply replaced some letters–most commonly ‘A’ and ‘E’–with numbers (‘A’ became ‘4’ and ‘E’ became ‘3’) so that searches for “hacker” would miss a “h4ck3r” Web page.
As Web-hacking grew in popularity and visibility, more and more people picked up on L33T, viewing it as a sort of code of communication used to signify membership in an elite community of computer users (hence the name, pronounced ‘leet’). This dialect became common among people discussing their ‘h4x’ (hacks) and their skills as “h4x0rz” (hackers).
In the mid-1990’s, online gaming provided a new environment for L33T. Many of the players of these new online multiplayer FPS’s (first person shooters) and RPG’s (role playing games) were also members (or at least followers) of the hacker communities, and boasted of their skills in these games in the same dialect they had used in boasting of their hacker triumphs: L33T. L33T became commonplace, at least in these limited communities.
L33T stayed relatively unknown to the larger Internet community until Megatokyo, a popular online comic, brought the dialect to a much larger audience. And while L33T remains mostly localized in gamer and hacker communities, aspects of it have been absorbed into the developing culture and community of the Internet as a whole (such as the respelling of ‘cool’ as ‘kewl’).
So, how does L33T work?
Though L33T is an incredibly flexible dialect and can take a variety of forms, its main principle is the mutation of basic written English by replacing letters in words with numbers and/or symbols. Spelling is also of little concern to those who use L33T–many terms in L33T are the results of typos or common misspellings.
pwn = a typo of ‘own’ or ‘0wn,’ meaning to handily defeat someone or something
teh = a common misspelling of ‘the’
Spellings of many words in L33T fall along phonetic lines.
sux = phonetic reproduction of ‘sucks,’ something that is unpleasant (i.e. ‘this sux’)
Then again, some words are treated in the exact opposite manner.
ph34r = ‘fear,’ commonly used as an imperative verb (i.e. ‘ph34r my l33t skillz!’)
Grammar or Lack Thereof
As you’ve already seen, basic l33t is just replacing vowels with numbers:
A = 4
E = 3
I = 1
O = 0
However l33t is a very flexible ‘language’ and you can go from this very basic l33t, to ultra 1337 by being creative; a few examples:
O = ()
U = |_|
T = 7
D = |)
W = //
S = $
There is no agreed-upon way to write l33t, so it’s up to you whether or not to go with light l33t, medium 1337, hard |_337 or even ultra |_33¯|¯. In this entry, ‘l33t’ is used except when referring to medium, hard or ultra ‘1337’.
Other Grammatical Oddities
The -0r clause can be used in place of -ed or -er, for example ‘1 0wnz0r!’ (most commonly seen in ultra 1337 as ‘1 0//||z0r!’) rather than ‘1 0wn3d’. However it can also be used like this, ‘1 4m l33t h4x0r!’ (in ultra 1337, ‘1 4|/| |_337 |-|4x0r!’) rather than, ‘1 4m 4 133t h4ck3r!’.
As a general rule, in l33t, rather than use ‘s’ to make something plural, a ‘z’ is used instead. Also ‘f’ is normally changed to ‘ph’. The short ‘u’ is often changed to ‘00’, as well.
Punctuation is usually left out with greater consistency as the level of l33t increases. Full stops are left out entirely because, when you are chatting online, where you would normally put a full stop you just hit ‘enter’ to send the message and keep typing. Exclamation marks are used quite a bit (and usually quite a number at once), mostly because l33t is most commonly used in expressions of pleasure. Commas are generally left out in hard and ultra 1337, and are uncommon in medium 1337.
Vocabulary
Although l33t speak is just a corrupted form of the English language, there are many phrases and words (spellings) that are unique to it.
0w|| or 0wn3d - One of the most popular l33t words it is very loosely defined as beaten or can simply be an expression of awe, for example, ‘I 0wn3d you’ means ‘I have beaten you in a very humiliating fashion’, or ‘0wn4ge!’ which means ‘That was (or is) very nifty’.
w00t - Derived from ‘hoot’, this is defined as ‘yay’, it can be used, for example, upon victory or, possibly, the release and procurement of a new video card.
13wt - Treasure, good merchandise, possessions, a misspelling of loot. Most commonly referring to pirated software, items in a game or promotional giveaways.
h4x0r - Hacker, can be used for a real hacker or simply a very skillful person. This is the most common occurrence of the -0r clause.
ph33r - Fear, most commonly used in such phrases as, ‘Ph33r m3!’ or ‘Ph33r |/|y 1337 sk1llz!’ It can also be written as, ‘ph34r’.
sk1llz - Obviously derived from ‘skill’, referring to skill in some type of online game, programming or hacking. Many times used in conjunction with ‘m4d’. As a general rule, if one has sk1llz, one is to be ph33r3d.
m4d - Mad, mostly used as a descriptive term meaning great, for example, ‘h3s g0t m4d sk1llz’.
j00 - You, commonly used in such phrases as, ‘j00 d34d f00’.
f00 - Fool, one who isn’t very bright or skillful.
j0 - Yo, as in the greeting.
d00d - Dude; an expression of comrade, or just used to address a random person online.
sux0r - Sucks, as in ‘7h1s sux0r’, one of the few common examples of the -0r clause.
l4m3r - Lamer, someone who is lame, someone who uses an unfair tactic or generally makes the things around him or her less fun.
n00b - Short for noobie, misspelling of newbie; someone who is new to something, or just not very good at it.
Courteousness
Although you can use l33t speak exclusively, it is looked down upon in most forums and chat rooms. The best place to use l33t speak is in a brief expression of excitement, when you are just playing around or in a supreme example of your geeky prowess.
