Brando is a website that sell all sort of USB Gadgets, here is another from them it is a Wireless USB Keypad that comes with a Trackball. The wireless keypad comes equipped with 19 standard keys, 13 hot keys and a high precision 1000DPI trackball. The keypad connects wireless using a 2.4 GHz radio frequency which will make it work with your laptop or even PC.
The Keypad weighs just about 143grams and measures 114 x 134 x 25mm. It is compatible with Microsoft Windows 2000/XP/Vista OS and will cost you only $37 to own it.