What sickens me is seeing an "F" inserted between the M and the G. It's increasingly common, and I don't exaggerate when I say I can't look at it head-on. I've even seen it used here on FR once or twice. People really, really need to think about what they're typing.
I teach 7th/8th grade in a Catholic school, and whenever a student uses “OMG” I stop and make them say out loud the Fatima Prayer (O my Jesus, forgive us our sins and save us from the fires of hell...) I have just about broken the habit and I now have students let me know when it happens.