Steve Ballmer recently visited Stanford GSB and CNET has an awesome eight minute clip of his talk. While his comments on Google’s growth and the four stages of a business (launch an idea, reach critical mass, milk the critical mass, and then regenerate the business to start at stage one) are interesting, the most impressive part is his overall enthusiasm and likeability, even while taking a jab at a competitor.
Then again, Steve Ballmer’s passion has never been a question. (See: Steve Ballmer going crazy or Steve Ballmer chanting "developers").