I have a vacant Thunderbolt 2 port on my iMac and thought it would be a simple thing to buy a dongle to adapt to USB 3. Not so; very few options, all well over $100, and ridiculous shipping costs. I know I can get a TB to Firewire 800 adapter (I'm using one already) but that means more daisy-chaining. If anyone has a TB to USB cable or adapter or hub or something that will allow me to connect a USB device I'm happy to pay for it. Bruce Whittington.