Actually TI still has to do his prison time but it dosen't seem to be holding back his career any. Here's the paragraph from an aricle mtv posted about it back when he was arrested.

As part of his sentence, T.I. (born Clifford Harris Jr.) must complete at least 1,000 hours of community service talking to kids about the ills of guns, drugs and gangs. According to the Atlanta Journal-Constitution, if the rapper abides by the conditions of his plea agreement, he will likely serve less than the one year and one day sentence that was imposed. That will be determined in March 2009, the paper reports. He was also sentenced to a year of home confinement, minus the time he's already served locked down in his Atlanta-area home to date.

One of T.I.'s attorneys, Ed Garland, told the paper that his client is free to "perform, act in movies [and] carry on with his business until the end of the 12-month period," though he will be shadowed by a private security officer at all times who will report on him if he strays from the court-appointed conditions. Even if he is able to promote Paper Trail later this year, the prison sentence will take T.I. off the scene for a long stretch for the second time in two years, an eternity in the here-today-gone-tomorrow-morning rap game.

There's never a good time to go to prison. But, depending on the trajectory of their careers, some artists can survive, or even thrive, during their time away, according to Chaz Williams, CEO of Black Hand Entertainment and manager of incarcerated rapper Foxy Brown.