Perhaps a little off-topic, please forgive ... Do ALL USB hubs work on MacIntoshes, or not ? I bought a cheap one from RadioShack, and it would not work at all - tried PalmPilot, iMic, and floppy drive. Dunno if some are somehow incompatible or if it was simply a faulty unit. Can anyone suggest some brand/models that are KNOWN to work (mine is a G4 tower). Thanks, John