There are many USB powered gadgets in the market which are useful and pratical but these two popular USB toys are just for plain fun.
USB Pepe parrot is available in a dual-powered format, runs on battery and also powered by plugging into the USB port on your labtop or desktop. This parrot listens to what you are saying and repeat at random intervals. Like a real parrot it flaps its wings when it repeat the phrases back. This cost around $20 and availabe online including amazon store.
USB Robot owl is cool, it can be clipped on top of your laptop with the included clip and the Owl blinks his eyes and turns his head from side to side in a quizzical manner. Plug him into any handy USB port and push the button on the back to choose from three owlish moods – Active, Mellow, or Sleeping. You can also set him on top of his comfortable stump. This also costs around $20 and available at amazon and other online retailers.