Spelling is certainly not a measure of intelligence. And, just as certainly, there are people with various problems such as dyslexia. I'm not offended by poor spelling or grammar, but it is definitely my preference to read something that is well written. However, I'd rather read interesting and useful text that is poorly written than well written drivel like much of this thread, and, without a doubt, including this addition to it of mine.
With all due respect to those with actual difficulties though, I believe that for the greater proportion of the culprits (not just on this site but generally as well), it is simply a matter of rushing while typing (resulting in typographical errors), not thinking much about what they're writing (which results in worse than grammatical errors some of the time), and not proofreading their posts. I always proofread; it doesn't take much time and I often find that I catch a few mistakes, or decide to rephrase something.
Now as much as I hate to admit it, I do lapse into netspeak occasionally. I've become quite comfortable with BTW, IMHO, and a variety of other terms. However, I don't think I'll ever feel that l8r, gr8, etcetera are appropriate. That is just me. But, I will agree with Zoe that posts, and emails, which have virtually no punctuation and feature netspeak jargon approximately every fourth word, are more difficult to comprehend. Undoubtably, I give them less of my attention, which, of course, does not necessarily matter to anyone, unless the person was specifically writing to me (which does happen quite a bit by email).
In the same manner that all microhylids are amphibians, but not all amphibians are microhylids, I believe that while poor spelling and grammar are not a sign of a lack of intelligence and effort, excellent spelling and grammar are indeed of function of either reasonable intelligence, effort, or both. Of course, a caveat about the preceding sentence- I'm referring to those circumstances where a person is attempting to communicate in their language of choice. I do have a great deal of respect for those who are working on their second (or third) language here on this forum; I shudder to think about what my attempts at typing in French would be like.
To summarize, do what you can, and please proofread your posts if you give a rat's a$$ about what anyone might think of them. If not, don't bother. IMHO, that is:-)
No can we plz get bcak to descusing sumthing mre useful?