Typing in "leetspeak" or otherwise mangling the language of discourse prevents your thoughts from being clearly understood by others. On a forum, your words are all that you have to convey what you're asking or saying. While smileys may be used to signify humorous intent, there is no adequate way to convey the nuances of non-verbal factors of communication. While I can decipher leetspeak and phonetic spellings, it's a pain to do so, and will create a perception on my side of the communication that the original poster is lazy or for lack of a better term, "communicationally challenged".
Approaching one of your comments about the savings of time mathematically - you say you can touch-type at about 60 words per minute. That's great. "Word" in the typing class I had during eighth grade in 1986 was defined as five letters. Following that logic, typing "u" instead of "you" is a savings of two letters. If 1 word = 5 letters, and you type 60 words/minute, then you're typing 300 letters/minute, so you save 2/300 of a minute, or approximately .4 seconds. That's not really that significant, and the scant time savings isn't really worth the negative impact that the perception of your words will receive in the eyes of many others.
The occasional spelling error I can tolerate far more than the laziness of "txtspeak". I don't expect everyone to spell perfectly, but at least come close, and, as others have mentioned, there's dictionary.com as a free resource.
If people would type, read, edit, then post things would be much easier. I don't claim to have perfect grammar or spelling, but I make the effort. Allowing yourself to fall into habits of typing what some can perceive as unintelligible combinations of ASCII characters will not serve you well if you ever have to type something in a professional environment.
Approaching one of your comments about the savings of time mathematically - you say you can touch-type at about 60 words per minute. That's great. "Word" in the typing class I had during eighth grade in 1986 was defined as five letters. Following that logic, typing "u" instead of "you" is a savings of two letters. If 1 word = 5 letters, and you type 60 words/minute, then you're typing 300 letters/minute, so you save 2/300 of a minute, or approximately .4 seconds. That's not really that significant, and the scant time savings isn't really worth the negative impact that the perception of your words will receive in the eyes of many others.
The occasional spelling error I can tolerate far more than the laziness of "txtspeak". I don't expect everyone to spell perfectly, but at least come close, and, as others have mentioned, there's dictionary.com as a free resource.
If people would type, read, edit, then post things would be much easier. I don't claim to have perfect grammar or spelling, but I make the effort. Allowing yourself to fall into habits of typing what some can perceive as unintelligible combinations of ASCII characters will not serve you well if you ever have to type something in a professional environment.

