An aquarium is a nice thing to have; especially if you don't need to ever feed the fish or clean the water. The USB Aquarium one of the geekiest toys you can keep on your desk this year. Click on the play button on the video if you don't believe :)

The USB Mini Desktop Aquarium is the home to two life-like tropical fish. Powered with your USB connection, a small motor generates a current in the water, allowing the fish to gently swim about the tank. The aquarium is equipped with a high-intensity blue LED that illuminates the tank in dark environment. Both motor and LED can be independently switched off. All you will need to do is to add water and plug it in to enjoy this nice USB aquarium for hours.  Available from Thinkgeek Electronicsfor US $19.99.