I have a few gadgets that I've tried to plug into my regular non-powered USB hub and it causes an 'overload on USB' error message, so I bought this powered one to see if that fixes the problem and it does!
You can use the TARDIS as a non-powered hub as well by just plugging it into your USB port and not using the power supply it comes with.
When you plug it into the USB port on your computer, the blue light on the top lights up and when you plug anything into the TARDIS itself, it makes the 'dematerialisation' noise and the light slowly flashes on and off. There is a button on the back to switch the sound off if it's getting on your nerves but mine will stay switched on....I half expect it to disappear when I plug things into it ;)
A fun addition to your desktop.