Ex-Microsoft mobile exec ends world's shortest retirementThis morning, according to Microsoft, Pieter Knook, the company's wireless chief, "retired" after 17 years with the company. "Retiring" sounds so much better than "leaving for a better gig," doesn't it? Knook is actually joining Vodafone to head a new Internet division. He starts March 10. Pieter, next time, why not tell people you're taking a vacation? That would be easier.