The UpCart is a trolley/cart that helps you haul large objects up and down stairs. The trolley is made up of 3 wheels that rotate when they hit a stair. On flat ground, the cart rides on two wheels with the third wheel sitting right above them, and once they run into a stair, they rotate around so that the wheel on the top is now the front wheel on the bottom, and then rinse and repeat for each stair you come across.

Available at amazon.com for $79.95