I installed two text-only consoles, in separate folders, and set them up. You have to give them a different machine ID, in order to run both at the same time.
Actually I don't think I ran all those three clients at the same time. I ran two text onlys on my C2D, and the GPU in a spare computer. Or it was text-only and GPU client on my C2D, while I had spare computers doing text-onlys.