I was so pleased with the Belkin USB hub (the silver one which said it was specially for Macs) that I got some more. http://catalog.belkin.com/IWCatProd...=&Section_Id=201526&pcount=&Product_Id=196181 Then more recently I've got the black ones which I thought were the same. http://catalog.belkin.com/IWCatProductPage.process?Product_Id=159070 Turns out only the silver ones supply power when the host computer is off. The 'power while computer not connected' is hugely useful because you can charge iPods, etc even if the computer's off. And if you're travelling, you can use the hub to charge up to 4 USB-charging devices at once - no need to take multiple bricks. I have looked underneath the hubs and there is a difference: The black ones are a "F5U234 Rev.3" while the silver ones are just "F5U234". I've bought the hubs ovbiously so there's no way I can change them but I thought I'd write this just in case it's useful for someone. My only question is: Why would Mac versions be rigged like this? It's an advantage obviously but just wondered if there was something in the Mac's USB2.0 implementation which made this a requirement.