You've probably seen them making the rounds on social media: the brain-busting, stutter-inducing questions asked in job interviews at places like Google (How many cows in Canada?), Apple (What are five ways to put a hole in a sheet of metal?), Dell (What songs best describe your work ethic?) and Novell (How would people communicate in a perfect world?). Less likely to be discussed is whether such interview questions actually help employers find the right IT pros.