Credits from ITT will not transfer to a real school.
GPC They will.

I don't suggest going to ITT at all, given the recession, and the10% pay cut APD just took, what if you decide to take a different path? You credit for GPC will transfer to GSU, GT, Kennesaw, etc...

Do this, stay enrolled at GPC, tell them you want to be a TRANSIENT student, meaning you stay enrolled at GPC, while attending classes on a different campus/school. They will give you a paper with transient student equivalent courses at the other schools. This way you can go to ITT, Atlanta Tech, GT, wherever and still be enrolled at GPC, just in case you change your mind.