I don't either. I don't overly abbreviate things. A lot of gamers do though (I type fast so I don't need to).
Hhaa.a... THX hahaa...i think everyone here should look at your clock.. wow so fast going to lunch time again... on line can pass your time so fast too
Strangely I always type in full in SMS - I don't know why. Maybe I'm too old school. But I have some exceptions here like simple contractions.