Make sure that if you do get a hub that it is a powered one, and that it is a USB 2.0 device. Some USB devices require that power is supplied, so I would be tempted to install a PCI controller if you do have a spare PCI slot, to avoid that particular problem.
You can pick up a four port PCI USB 2.0 card for about £25
Of all the Things I've lost, I miss my mind the most