Sit down and let professor manneman give you the tour. Here's how things work.
the written language is a different one then the spoken one in many ways. The most importent one being that you can not see the reciever of your statements. That is why written language is so up tight. You want as little as possible to be missinterpreted.
The written language is "the real" one, or at least the one that we base our written language on.
Having said that, we take a look at the internet and the comunications we have there. I think that in a forum, such as this, there is a sort of blend between the spoken and the written language. Mainly beacuse most posts are in a sort of conversational tone and that you acually have the option to go back and edit a post or post an explaining one.
As long as the message gets through it doesn't really matter what kind of grammar you use beacuse the language of choise has done what it was intended to do. Carry the message.
I for one would be more concerned if everyone started writing in 1800-century english just so that they could avoid using words that doesn't exist and modern "bad" grammar.
Class dismissed