I just finished College English and since I am only 19 I probably do type faster then I can think.
That illustrates how the computer may be the downfall of human language.
Back when people had to write by hand or use a typewriter, they had to think and plan before writing.
The computer frees us from that limitation. It is potentially a powerful composition tool that gives us the ability to transform our thoughts into words and
then ogranize, rearrange, and edit them. With such power available, the average person should be able to compose masterpieces of literature.
Unfortunately, the average person seems to see the composition power of the computer and think, "Well, if make a typo, there's a backspace key."
They go from not caring about spelling to not caring about whether or not their sentences are formed correctly. Then, they don't care if a paragraph is coherent. Then, they don't care if the paper they wrote even says anything.
The mistakes get bigger and harder to correct with a backspace key.
If you really love langauge (or even just computers), I'd advise you to follow CC's advice and think before you type. If you do, then the relative speed of each will no longer matter.
I am probably more used to informal writing due to my vast years with AOL Instant Messenger and that is most likely why minor grammatical mistakes have yet to boil my blood.
It's important to realize
why instant messaging is "allowed" to be less formal. If you send a message that your single-person audience misunderstands, he or she can always ask you for clarification. When making a forum post, you're often writing to many people, and you usually only get one shot at making your point.
When writing, you should also keep in mind your goal. Are you writing something because you want to convey information, or because you want to follow a prescriptive grammar?
When you're writing to convery information and you're faced with something like whether or not to put a preposition at the end of a sentence, and following a prescriptive grammar rule makes your goal harder to accomplish, then you question the rule, and perhaps ignore it.
If enough people find good reason to ignore the rule in enough cases, it won't be a rule after a while, anyway.
A prescriptive grammar is a tool for making yourself understandable. In many situations, failing to use that tool is inadvisable; some situations, however, call for alternate tools.