I have to admit, when a post shows up in forums or on blogs using text message-ese, I find it frustrating as hell. I've always thought of this type of thing as a lazy writer who can't be bothered to type out full words and would rather make the reader take extra time to figure out what is being said.
But lately I've been text messaging more and using IM apps like Twitter. And I'm thinking if you avoid the lure of the cryptic syntax, these types of venues could actually make you a BETTER writer.
Why? Simply, it forces you to be concise. You're limited to a mere 155 characters to get your thought across. Using full sentences, you need to get pretty creative and pick just the right words to say what you want in that limited amount of space. If this translated over into fiction writing, it would be nothing but good. Think of all that passive voice and exposition that would never fester up a novel's pages!
Of course, we learned this kind of thing in High School when I was a kid, but we called them précis and Haiku. But it's a lot more fun when you know there's a live source on the other end receiving your messages.
Just make sure you use full words. I have to expend enough effort in all the other areas of my life without trying to figure out what you're saying.