I agree with mook.
Txt Spk is chav by association. Should be banned everywhere IMHO. That said, ROFL etc are acceptable, as they are acronyms not chav shortenings. Hence PSC, GT, ECU etc are fine (and, for that matter etc itself...) but incorrect usage of language is not.
And* dont give me any of that nonsense about grammar being 'the correct usage of words - this is how I talk therefore its ok' - its not, ban it now. Seriously, to those of you who have got used to writing it, you will benefit hugely from de-learning. It would the same effect on peoples perceiption of you as learning where the is G-spot would have on your sex life.
I'll all up for freedom of expression, but language is so important to making your point (and more importantly making your point well) it merits the censorship of txt spk.
*I am aware I used and at the start of a sentence, but hey...