127 daisy chained from just one port, if my memory is correct. Which usually, it isn't.
Personally, I prefer to use a powered hub over a pci card. I like the belkin 7 port hub. Fits on the desktop and is self powered. It just uses one rear usb port.
I think the only problem should come from the power consumed from the usb devices, thats why the powered hubs are so popular.