A USB hub in one of your rear sockets would bring access round to the side of the machine. They're cheap and cheerful from a variety of suppliers e.g. Belkin in PC World, or DABS, etc, etc.
I think a front tray is also available which plugs in to a forward mounted USB socket on your Mobo. Refer to the manual. These are available, I think, from Maplin Electronics or Overclockers and also sometimes come with a firewire socket as well. A look in the likes of Computer Buyer or Shopper might also dig up a nugget from their advertisers.