steve359: I've got external powered hub with adequate space. Problem is that Apple recommends that Timemachine and keyboard both be directly plugged into iMac. APC recommends that UPS be directly plugged into iMac. That leaves everything else which goes through the hub. I need to get a new external HD (my Iomega died). If anyone knows of a good external HD that allows connection by usb and has an auxilliary usb port so my hub can go through that, it might work. The Iomega used firewire so it didn't compete for iMac usb ports, but I'd prefer to have a usb HD.
seventy one: Rechecked. My iMac has 3 usb ports and two firewire.