In Tokyo yesterday, engineers showed off a range of advanced machines at the 2007 International Robot Exhibition, the nation's top robotics showcase.

On display were a Rubik's Cube-solving machine, a panda-like bot designed to relieve stress in the people it interacts with, and a new dental training robot, Simroid, that features a realistic mouth and false teeth embedded with sensors. (And sort of looks like it's been struck by Jack Nicholson's Joker.) If an aspiring dentist drills in the wrong spot, Simroid emits a protest, letting the student know he or she has erred. The robot is not ready for production just yet, so young dentists will continue practicing on cash-strapped grad students.—Gregory Mone

Via AP