Another oddball USB gadget from Thanko: to complement its fan-equipped mouse and keyboard for cooling your hands, Thanko also has a fan-equipped seat for cooling your... er, seat. The "USB Cooler Cushion" straps onto your work chair and, taking power from a USB cable to your computer, sends cooling air upward through pores in the cushion. With a USB adapter for your car's cigarette lighter, it'll keep you comfy on the road too. Says the company's English page: "No more sweaty nasty seat for me!!" JPY4800 (JPY5280 with car USB adapter).
More info (Japanese):
http://thanko.jp/usbseatair/
(English):
http://www.raremonoshop.com/us/product-information/usb-cooler-cushion.html
USB Cooler mouse and keyboard (English):
http://www.tekronomicon.com/gadget/2008/07/usb_cooler_mouse
http://www.tekronomicon.com/gadget/2008/08/usb_cooler_keyboard