I just added two StarTech 4 port PCI-E USB cards to my pro- Microcenter was the only place local I could find any PCI-E USB cards. With both cards in, I had to do a lot of port swapping to get everything to work... Neither the iPod or iPhone docks would work unless they were plugged into an internal port instead of the card, and some things wouldn't work in some ports on some cards. (Griffin Powermate, Keyspan USB-Serial, Huey). I took one of the cards out and got everything to work, but I lose the USB card after the machine wakes from sleep. They come back after a re-boot. My Macalley USB Hub/Card Reader won't work at all with them. FWIW, the cards weren't marked as "Mac Compatible". I'm not keen on a hub, as the only place I'll have to plug it in would be a front port.