LinkedIn. Facebook. Twitter. What are you on? We recently asked 1,987 HR and business professionals the following question: Which social networking tools do you use? Here are the responses: LinkedIn only: 14% Facebook only: 16% Twitter only: 0.3% LinkedIn and Facebook: 31% Facebook and Twitter: 3% LinkedIn and Twitter: 1% LinkedIn, Facebook and Twitter: 9% None:27% Let’s break it down . . . Looks like more and more [...]