This video explains it best:
Researchers at the Coordinated Robotics Lab of the University of California, San Diego, have demonstrated a Balancing and Climbing Robot.
The "iLean" has a segway-like basic structure consisting of two large wheels and a pole. On encountering an obstacle, such as a large rock or the step of a staircase, the robot's main body can lean it's pole against the obstacle and then climb up the pole till it tumbles over the rock or on to the next step.
Next to the "iLean" robot, the same group has also released a jumping version called the "iHop" - see video below:
For more information you may want to have a read over an interview with the developers or check these links:
Coordinated Robotics Lab at UC San Diego