T.I. Pleads Guilty -- Going to the Slammer

Rapper T.I. has just plead guilty to federal weapons possession charges -- and will spend one year behind bars!

T.I., real name Clifford Harris, will begin his sentence after completing at least 1,000 hours of community service -- talking to kids about the dangers of drugs, gangs and guns.

The rapper plead guilty to possession of an unregistered firearm, possession of machine guns and possession of a firearm by a convicted felon.