Twenty UW-Madison MBA students lunched on New York strip steaks, french fries and root-beer floats with billionaire Warren Buffett in his hometown of Omaha last Friday ? on Buffett?s tab. And they came back with lessons to chew on about business, investing and life. The School of Business graduate students were among 160 students from eight colleges and universities around the country who were chosen for a chance to meet with Buffett and ask him questions.