I know I have seen combo USB/FW hubs, but I can't provide too much help there.
On the other hand, I really like this hub from Belkin. It is black and silver, relatively sexy, and has top-loading slots that work great with my shuffle.
The USB and FireWire prots are seperate. To use the FireWire ports from your computer, you have to plug it into a FireWire port on the computer. And the USB side has to be connected to the computer as well.